Skip to search results Skip to filters Skip to sort Skip to selected filters

Convertible Satchel

70 items found

Sort By

Your Selections

Search Results

. HOBO - Sheila Medium. Color White. Low Stock. $328.00. 3.6 out of 5 stars

8 left in stock

Brand Name: HOBO
Product Name: Sheila Medium
Color: White
Price: $328.00
Rating: 4Rated 4 stars out of 5(7)

HOBO - Sheila Medium. Color Black. Low Stock. On sale for $286.20. MSRP $318.00..

2 left in stock

Brand Name: HOBO
Product Name: Sheila Medium
Color: Black
Price: $286.20MSRP: $318.00
Rating

Frye - Aubrey Satchel. Color Cognac. Low Stock. On sale for $182.36. MSRP $388.00..

10 left in stock

Brand Name: Frye
Product Name: Aubrey Satchel
Color: Cognac
Price: $182.36MSRP: $388.00
Rating

MICHAEL Michael Kors - Marilyn Medium Satchel. Color Crimson. On sale for $134.10. MSRP $298.00..

Red MICHAEL Michael Kors Marilyn Medium Satchel

Brand Name: MICHAEL Michael Kors
Product Name: Marilyn Medium Satchel
Color: Crimson
Price: $134.10MSRP: $298.00
Rating

Dooney & Bourke - Florentine Small Satchel. Color Natural/Natural Trim. Low Stock. On sale for $396.00. MSRP $528.00.. 4.3 out of 5 stars

1 left in stock

Tan Dooney & Bourke Florentine Small Satchel

Brand Name: Dooney & Bourke
Product Name: Florentine Small Satchel
Color: Natural/Natural Trim
Price: $396.00MSRP: $528.00
Rating: 4Rated 4 stars out of 5(52)

MICHAEL Michael Kors - Marilyn Medium Satchel. Color French Blue Multi. Low Stock. $298.00. 2.5 out of 5 stars

1 left in stock

Blue MICHAEL Michael Kors Marilyn Medium Satchel

Brand Name: MICHAEL Michael Kors
Product Name: Marilyn Medium Satchel
Color: French Blue Multi
Price: $298.00
Rating: 3Rated 3 stars out of 5(2)

Brahmin - Finley Carryall. Color Fairest Grey. Low Stock. $395.00. 5.0 out of 5 stars

4 left in stock

Brand Name: Brahmin
Product Name: Finley Carryall
Color: Fairest Grey
Price: $395.00
Rating: 5Rated 5 stars out of 5(2)

Brahmin - Duxbury Satchel. Color Buttercup. Low Stock. $295.00. 5.0 out of 5 stars

2 left in stock

Brand Name: Brahmin
Product Name: Duxbury Satchel
Color: Buttercup
Price: $295.00
Rating: 5Rated 5 stars out of 5(1)

Kate Spade New York - Katy Textured Leather Medium Top-Handle Satchel. Color Rock Garden. On sale for $238.80. MSRP $398.00.. 5.0 out of 5 stars

Green Kate Spade New York Katy Textured Leather Medium Top-Handle Satchel

Brand Name: Kate Spade New York
Product Name: Katy Textured Leather Medium Top-Handle Satchel
Color: Rock Garden
Price: $238.80MSRP: $398.00
Rating: 5Rated 5 stars out of 5(1)

MICHAEL Michael Kors - Marilyn Medium Satchel. Color Vanilla/Acorn. Low Stock. $298.00.

7 left in stock

Beige MICHAEL Michael Kors Marilyn Medium Satchel

Brand Name: MICHAEL Michael Kors
Product Name: Marilyn Medium Satchel
Color: Vanilla/Acorn
Price: $298.00
Rating

Dooney & Bourke - Pebble II Small Barlow. Color Black. Low Stock. On sale for $275.94. MSRP $378.00..

3 left in stock

Black Dooney & Bourke Pebble II Small Barlow

Brand Name: Dooney & Bourke
Product Name: Pebble II Small Barlow
Color: Black
Price: $275.94MSRP: $378.00
Rating

Dooney & Bourke - Pebble II Barlow. Color White. Low Stock. On sale for $316.72. MSRP $428.00.. 5.0 out of 5 stars

2 left in stock

Brand Name: Dooney & Bourke
Product Name: Pebble II Barlow
Color: White
Price: $316.72MSRP: $428.00
Rating: 5Rated 5 stars out of 5(2)

Hammitt - Addie Medium. Color Toast Tan/Brushed Silver. Low Stock. On sale for $329.30. MSRP $445.00.. 5.0 out of 5 stars

5 left in stock

Brand Name: Hammitt
Product Name: Addie Medium
Color: Toast Tan/Brushed Silver
Price: $329.30MSRP: $445.00
Rating: 5Rated 5 stars out of 5(1)

Kate Spade New York - Katy Textured Leather Satchel. Color Black. Low Stock. On sale for $398.00. MSRP $428.00..

7 left in stock

Black Kate Spade New York Katy Textured Leather Satchel

Brand Name: Kate Spade New York
Product Name: Katy Textured Leather Satchel
Color: Black
Price: $398.00MSRP: $428.00
Rating

HOBO - Sheila Small Satchel. Color Black. On sale for $128.96. MSRP $248.00.. 4.0 out of 5 stars

Brand Name: HOBO
Product Name: Sheila Small Satchel
Color: Black
Price: $128.96MSRP: $248.00
Rating: 4Rated 4 stars out of 5(2)

GUESS - Stephi Bamboo Flap. Color Brown Logo. Low Stock. On sale for $103.46. MSRP $138.00..

7 left in stock

Brand Name: GUESS
Product Name: Stephi Bamboo Flap
Color: Brown Logo
Price: $103.46MSRP: $138.00
Rating

Anne Klein - Convertible Top-Handle Satchel with Horsebit. Color Stone/Gold Logo. On sale for $73.10. MSRP $85.00..

Gold Anne Klein Convertible Top-Handle Satchel with Horsebit

Brand Name: Anne Klein
Product Name: Convertible Top-Handle Satchel with Horsebit
Color: Stone/Gold Logo
Price: $73.10MSRP: $85.00
Rating

ALDO - Balki. Color Bone. On sale for $50.96. MSRP $68.00..

Brand Name: ALDO
Product Name: Balki
Color: Bone
Price: $50.96MSRP: $68.00
Rating

Patricia Nash - Lyon Satchel Crossbody. Color French Riviera. Low Stock. On sale for $209.16. MSRP $249.00.. 5.0 out of 5 stars

3 left in stock

Navy Patricia Nash Lyon Satchel Crossbody

Brand Name: Patricia Nash
Product Name: Lyon Satchel Crossbody
Color: French Riviera
Price: $209.16MSRP: $249.00
Rating: 5Rated 5 stars out of 5(9)

LAUREN Ralph Lauren - Leather Large Marcy Satchel. Color Vanilla. Low Stock. On sale for $370.50. MSRP $475.00.. 5.0 out of 5 stars

1 left in stock

Bone LAUREN Ralph Lauren Leather Large Marcy Satchel

Brand Name: LAUREN Ralph Lauren
Product Name: Leather Large Marcy Satchel
Color: Vanilla
Price: $370.50MSRP: $475.00
Rating: 5Rated 5 stars out of 5(1)

Bed Stu - Rockababy. Color Rowan Teak Multi. Low Stock. $270.00. 3.8 out of 5 stars

3 left in stock

Brand Name: Bed Stu
Product Name: Rockababy
Color: Rowan Teak Multi
Price: $270.00
Rating: 4Rated 4 stars out of 5(11)

Kate Spade New York - Gramercy Medium Satchel. Color Cordovan. $448.00.

Burgundy Kate Spade New York Gramercy Medium Satchel

Brand Name: Kate Spade New York
Product Name: Gramercy Medium Satchel
Color: Cordovan
Price: $448.00
Rating

Brahmin - Melbourne Large Duxbury Satchel. Color Icy Python. Low Stock. On sale for $241.50. MSRP $345.00.. 4.9 out of 5 stars

6 left in stock

Olive Brahmin Melbourne Large Duxbury Satchel

Brand Name: Brahmin
Product Name: Melbourne Large Duxbury Satchel
Color: Icy Python
Price: $241.50MSRP: $345.00
Rating: 5Rated 5 stars out of 5(23)

ALDO - Surgoinee. Color Black. On sale for $57.16. MSRP $65.00.. 5.0 out of 5 stars

Brand Name: ALDO
Product Name: Surgoinee
Color: Black
Price: $57.16MSRP: $65.00
Rating: 5Rated 5 stars out of 5(1)

HOBO - Sheila Satchel. Color Black/White. Low Stock. On sale for $139.10. MSRP $368.00.. 5.0 out of 5 stars

7 left in stock

Brand Name: HOBO
Product Name: Sheila Satchel
Color: Black/White
Price: $139.10MSRP: $368.00
Rating: 5Rated 5 stars out of 5(1)

ALDO - Legoirii. Color Other Dark Beige. Low Stock. On sale for $42.81. MSRP $65.00..

2 left in stock

Brand Name: ALDO
Product Name: Legoirii
Color: Other Dark Beige
Price: $42.81MSRP: $65.00
Rating

Fossil - Carlie Mini Satchel. Color Black. Low Stock. On sale for $120.77. MSRP $195.00..

5 left in stock

Brand Name: Fossil
Product Name: Carlie Mini Satchel
Color: Black
Price: $120.77MSRP: $195.00
Rating

Anuschka - Multi Compartment Satchel 690. Color Jungle Queen. Low Stock. $278.00.

3 left in stock

Multi Anuschka Multi Compartment Satchel 690

Brand Name: Anuschka
Product Name: Multi Compartment Satchel 690
Color: Jungle Queen
Price: $278.00
Rating

Brahmin - Melbourne Caroline Satchel. Color Sapphire. Low Stock. On sale for $310.50. MSRP $345.00.. 4.3 out of 5 stars

1 left in stock

Brand Name: Brahmin
Product Name: Melbourne Caroline Satchel
Color: Sapphire
Price: $310.50MSRP: $345.00
Rating: 4Rated 4 stars out of 5(3)

Dooney & Bourke - Maritime Satchel. Color Brown. Low Stock. On sale for $246.00. MSRP $328.00..

1 left in stock

Brand Name: Dooney & Bourke
Product Name: Maritime Satchel
Color: Brown
Price: $246.00MSRP: $328.00
Rating

Dooney & Bourke - Pebble Domed Satchel. Color Caramel. Low Stock. On sale for $198.36. MSRP $348.00.. 5.0 out of 5 stars

1 left in stock

Brown Dooney & Bourke Pebble Domed Satchel

Brand Name: Dooney & Bourke
Product Name: Pebble Domed Satchel
Color: Caramel
Price: $198.36MSRP: $348.00
Rating: 5Rated 5 stars out of 5(5)

MICHAEL Michael Kors - Chantal Small Messenger. Color Optic White. Low Stock. On sale for $213.20. MSRP $328.00..

6 left in stock

White MICHAEL Michael Kors Chantal Small Messenger

Brand Name: MICHAEL Michael Kors
Product Name: Chantal Small Messenger
Color: Optic White
Price: $213.20MSRP: $328.00
Rating

Dooney & Bourke - Maritime Barrel Satchel. Color Brown. Low Stock. On sale for $200.08. MSRP $328.00..

1 left in stock

Brown Dooney & Bourke Maritime Barrel Satchel

Brand Name: Dooney & Bourke
Product Name: Maritime Barrel Satchel
Color: Brown
Price: $200.08MSRP: $328.00
Rating

LAUREN Ralph Lauren - Peyton 31. Color White. Low Stock. On sale for $487.50. MSRP $625.00.. 4.0 out of 5 stars

1 left in stock

Brand Name: LAUREN Ralph Lauren
Product Name: Peyton 31
Color: White
Price: $487.50MSRP: $625.00
Rating: 4Rated 4 stars out of 5(2)

Dooney & Bourke - Saffiano Domed Zip Satchel. Color Coral. Low Stock. $328.00. 4.3 out of 5 stars

1 left in stock

Coral Dooney & Bourke Saffiano Domed Zip Satchel

Brand Name: Dooney & Bourke
Product Name: Saffiano Domed Zip Satchel
Color: Coral
Price: $328.00
Rating: 4Rated 4 stars out of 5(3)

Anne Klein - Medium Embossed Logo Satchel With Turn Lock. Color Chestnut. $88.00.

Brand Name: Anne Klein
Product Name: Medium Embossed Logo Satchel With Turn Lock
Color: Chestnut
Price: $88.00
Rating

Dooney & Bourke - Pebble II Domed Satchel. Color Caribbean Blue. Low Stock. On sale for $184.76. MSRP $298.00..

1 left in stock

Blue Dooney & Bourke Pebble II Domed Satchel

Brand Name: Dooney & Bourke
Product Name: Pebble II Domed Satchel
Color: Caribbean Blue
Price: $184.76MSRP: $298.00
Rating

Dooney & Bourke - Pebble Large Domed Satchel. Color Caribbean Blue. Low Stock. On sale for $236.60. MSRP $338.00.. 5.0 out of 5 stars

1 left in stock

Blue Dooney & Bourke Pebble Large Domed Satchel

Brand Name: Dooney & Bourke
Product Name: Pebble Large Domed Satchel
Color: Caribbean Blue
Price: $236.60MSRP: $338.00
Rating: 5Rated 5 stars out of 5(3)

Brahmin - Ombre Mini Melbourne Caroline Satchel. Color Bluestone. Low Stock. On sale for $310.50. MSRP $345.00.. 5.0 out of 5 stars

1 left in stock

Blue Brahmin Ombre Mini Melbourne Caroline Satchel

Brand Name: Brahmin
Product Name: Ombre Mini Melbourne Caroline Satchel
Color: Bluestone
Price: $310.50MSRP: $345.00
Rating: 5Rated 5 stars out of 5(1)

Anuschka - Medium Satchel 697. Color African Adventure. Low Stock. $328.00.

3 left in stock

Brand Name: Anuschka
Product Name: Medium Satchel 697
Color: African Adventure
Price: $328.00
Rating

MCM - Aren Bandana VI Boston Small. Color Black. Low Stock. $930.00.

1 left in stock

Brand Name: MCM
Product Name: Aren Bandana VI Boston Small
Color: Black
Price: $930.00
Rating

Anuschka - Zip Around Classic Satchel 625. Color Cleopatra's Leopard. Low Stock. On sale for $258.00. MSRP $268.00..

1 left in stock

Multi Anuschka Zip Around Classic Satchel 625

+2 colors/patterns

Brand Name: Anuschka
Product Name: Zip Around Classic Satchel 625
Color: Cleopatra's Leopard
Price: $258.00MSRP: $268.00
Rating

MICHAEL Michael Kors - Marilyn Medium Satchel. Color Black. Low Stock. On sale for $294.99. MSRP $298.00..

1 left in stock

Black MICHAEL Michael Kors Marilyn Medium Satchel

Brand Name: MICHAEL Michael Kors
Product Name: Marilyn Medium Satchel
Color: Black
Price: $294.99MSRP: $298.00
Rating

GUESS - Rea Small High Society Satchel. Color Brown Logo. Low Stock. On sale for $88.46. MSRP $118.00..

2 left in stock

Brown GUESS Rea Small High Society Satchel

Brand Name: GUESS
Product Name: Rea Small High Society Satchel
Color: Brown Logo
Price: $88.46MSRP: $118.00
Rating

Brahmin - Large Duxbury Satchel. Color Fairest Grey. Low Stock. $385.00.

6 left in stock

Brand Name: Brahmin
Product Name: Large Duxbury Satchel
Color: Fairest Grey
Price: $385.00
Rating

Bed Stu - Rockaway. Color Teak Rustic. Low Stock. On sale for $285.00. MSRP $325.00.. 4.2 out of 5 stars

1 left in stock

Brand Name: Bed Stu
Product Name: Rockaway
Color: Teak Rustic
Price: $285.00MSRP: $325.00
Rating: 4Rated 4 stars out of 5(36)

ALDO - Nanadi. Color Black. On sale for $48.71. MSRP $65.00..

Brand Name: ALDO
Product Name: Nanadi
Color: Black
Price: $48.71MSRP: $65.00
Rating

Patricia Nash - Antica Mini Frame Satchel. Color Parisian Newspaper. Low Stock. On sale for $135.20. MSRP $169.00.. 4.3 out of 5 stars

3 left in stock

Khaki Patricia Nash Antica Mini Frame Satchel

Brand Name: Patricia Nash
Product Name: Antica Mini Frame Satchel
Color: Parisian Newspaper
Price: $135.20MSRP: $169.00
Rating: 4Rated 4 stars out of 5(10)

Bed Stu - Miriam. Color Oats Dip-Dye. Low Stock. $375.00.

2 left in stock

Brand Name: Bed Stu
Product Name: Miriam
Color: Oats Dip-Dye
Price: $375.00
Rating

Anuschka - Wide Organizer Satchel 695. Color Rainbow Birds. Low Stock. $258.00. 5.0 out of 5 stars

2 left in stock

Blue Anuschka Wide Organizer Satchel 695

Brand Name: Anuschka
Product Name: Wide Organizer Satchel 695
Color: Rainbow Birds
Price: $258.00
Rating: 5Rated 5 stars out of 5(1)

Brahmin - Alamosa Small Caroline Satchel. Color Dune. Low Stock. On sale for $255.50. MSRP $365.00.. 5.0 out of 5 stars

1 left in stock

Taupe Brahmin Alamosa Small Caroline Satchel

Brand Name: Brahmin
Product Name: Alamosa Small Caroline Satchel
Color: Dune
Price: $255.50MSRP: $365.00
Rating: 5Rated 5 stars out of 5(1)

Brahmin - Melbourne Small Finley Satchel. Color Nocturnal. Low Stock. On sale for $255.50. MSRP $365.00..

3 left in stock

Black Brahmin Melbourne Small Finley Satchel

Brand Name: Brahmin
Product Name: Melbourne Small Finley Satchel
Color: Nocturnal
Price: $255.50MSRP: $365.00
Rating

Brahmin - Bowlin Duxbury Satchel. Color Fig Jam. Low Stock. On sale for $248.50. MSRP $355.00..

9 left in stock

Brand Name: Brahmin
Product Name: Bowlin Duxbury Satchel
Color: Fig Jam
Price: $248.50MSRP: $355.00
Rating

Bed Stu - Bruna. Color Teak Rustic/Black Rustic. Low Stock. $285.00. 4.0 out of 5 stars

7 left in stock

Brand Name: Bed Stu
Product Name: Bruna
Color: Teak Rustic/Black Rustic
Price: $285.00
Rating: 4Rated 4 stars out of 5(2)

HOBO - Sheila Zip Top Small Crossbody. Color Black. Low Stock. On sale for $206.36. MSRP $268.00..

1 left in stock

Black HOBO Sheila Zip Top Small Crossbody

Brand Name: HOBO
Product Name: Sheila Zip Top Small Crossbody
Color: Black
Price: $206.36MSRP: $268.00
Rating

Fossil - Heritage Top-Handle. Color Red. Low Stock. On sale for $194.88. MSRP $350.00..

5 left in stock

Brand Name: Fossil
Product Name: Heritage Top-Handle
Color: Red
Price: $194.88MSRP: $350.00
Rating

Dooney & Bourke - Gretta Domed Satchel. Color White. Low Stock. On sale for $199.66. MSRP $298.00..

1 left in stock

White Dooney & Bourke Gretta Domed Satchel

Brand Name: Dooney & Bourke
Product Name: Gretta Domed Satchel
Color: White
Price: $199.66MSRP: $298.00
Rating

Brahmin - Ellacoya Small Caroline Satchel. Color Oyster Grey. Low Stock. On sale for $328.50. MSRP $365.00.. 5.0 out of 5 stars

1 left in stock

Pewter Brahmin Ellacoya Small Caroline Satchel

Brand Name: Brahmin
Product Name: Ellacoya Small Caroline Satchel
Color: Oyster Grey
Price: $328.50MSRP: $365.00
Rating: 5Rated 5 stars out of 5(1)

HOBO - Sheila Zip Top Small Crossbody. Color Mirror Cheetah. Low Stock. On sale for $155.44. MSRP $268.00.. 3.0 out of 5 stars

7 left in stock

Multi HOBO Sheila Zip Top Small Crossbody

Brand Name: HOBO
Product Name: Sheila Zip Top Small Crossbody
Color: Mirror Cheetah
Price: $155.44MSRP: $268.00
Rating: 3Rated 3 stars out of 5(2)

Dooney & Bourke - Pebble Zip Zip Satchel. Color Oyster w/ Tan Trim. Low Stock. On sale for $202.64. MSRP $298.00.. 4.7 out of 5 stars

2 left in stock

Gray Dooney & Bourke Pebble Zip Zip Satchel

Brand Name: Dooney & Bourke
Product Name: Pebble Zip Zip Satchel
Color: Oyster w/ Tan Trim
Price: $202.64MSRP: $298.00
Rating: 5Rated 5 stars out of 5(60)

Brahmin - Melbourne Duxbury Satchel. Color Pecan. Low Stock. $295.00. 4.6 out of 5 stars

1 left in stock

Brand Name: Brahmin
Product Name: Melbourne Duxbury Satchel
Color: Pecan
Price: $295.00
Rating: 5Rated 5 stars out of 5(24)

Steve Madden - Bmickey XL Satchel. Color Cognac. Low Stock. On sale for $44.05. MSRP $49.00..

3 left in stock

Brand Name: Steve Madden
Product Name: Bmickey XL Satchel
Color: Cognac
Price: $44.05MSRP: $49.00
Rating

Steve Madden - Bmickey Satchel. Color Oatmilk. On sale for $79.16. MSRP $88.00..

Brand Name: Steve Madden
Product Name: Bmickey Satchel
Color: Oatmilk
Price: $79.16MSRP: $88.00
Rating

Kate Spade New York - Knott Tulip Toss Embossed Pebbled Leather Medium Satchel. Color Cream Multi. Low Stock. On sale for $321.30. MSRP $378.00..

1 left in stock

Multi Kate Spade New York Knott Tulip Toss Embossed Pebbled Leather Medium Satchel

Brand Name: Kate Spade New York
Product Name: Knott Tulip Toss Embossed Pebbled Leather Medium Satchel
Color: Cream Multi
Price: $321.30MSRP: $378.00
Rating

Karl Lagerfeld Paris - Ikons Satchel. Color Brown Leopard. Low Stock. On sale for $170.96. MSRP $228.00..

4 left in stock

Animal Print Karl Lagerfeld Paris Ikons Satchel

+2 colors/patterns

Brand Name: Karl Lagerfeld Paris
Product Name: Ikons Satchel
Color: Brown Leopard
Price: $170.96MSRP: $228.00
Rating

MICHAEL Michael Kors - Ruby Medium Satchel. Color Amazon Green. Low Stock. On sale for $322.20. MSRP $358.00..

1 left in stock

Green MICHAEL Michael Kors Ruby Medium Satchel

Brand Name: MICHAEL Michael Kors
Product Name: Ruby Medium Satchel
Color: Amazon Green
Price: $322.20MSRP: $358.00
Rating

MICHAEL Michael Kors - Williamsburg Small Bowling Satchel. Color Vanilla Multi. Low Stock. On sale for $196.80. MSRP $328.00..

6 left in stock

Multi MICHAEL Michael Kors Williamsburg Small Bowling Satchel

Brand Name: MICHAEL Michael Kors
Product Name: Williamsburg Small Bowling Satchel
Color: Vanilla Multi
Price: $196.80MSRP: $328.00
Rating

MICHAEL Michael Kors - Williamsburg Small Bowling Satchel. Color Black. Low Stock. On sale for $288.64. MSRP $328.00..

2 left in stock

Black MICHAEL Michael Kors Williamsburg Small Bowling Satchel

Brand Name: MICHAEL Michael Kors
Product Name: Williamsburg Small Bowling Satchel
Color: Black
Price: $288.64MSRP: $328.00
Rating

Brahmin - Melbourne Small Caroline Satchel. Color Cliffside. Low Stock. On sale for $227.50. MSRP $325.00.. 5.0 out of 5 stars

2 left in stock

Gray Brahmin Melbourne Small Caroline Satchel

Brand Name: Brahmin
Product Name: Melbourne Small Caroline Satchel
Color: Cliffside
Price: $227.50MSRP: $325.00
Rating: 5Rated 5 stars out of 5(1)

Brahmin - Ombre Melbourne Marissa Satchel. Color Horizon. Low Stock. On sale for $241.50. MSRP $345.00.. 2.0 out of 5 stars

1 left in stock

Purple Brahmin Ombre Melbourne Marissa Satchel

Brand Name: Brahmin
Product Name: Ombre Melbourne Marissa Satchel
Color: Horizon
Price: $241.50MSRP: $345.00
Rating: 2Rated 2 stars out of 5(1)

Convertible Satchel

Your Selections

Search Results

Get on the List

About Zappos

Customer Service

Resources

Explore Zappos