![Series 2: Medium Expandable Duffle Duffel Bags Knack Midnight Black](http://knackbags.com/cdn/shop/products/duffel1.jpg?v=1660438182&width=3840)
![Convertible Duffel Duffel Bags Knack](http://knackbags.com/cdn/shop/files/duffel_280c9dd7-e176-4cfd-8771-de18e775e423.jpg?v=1695871540&width=3840)
![Convertible Duffel Duffel Bags Knack](http://knackbags.com/cdn/shop/files/duffelunexpanded_7fb74526-6b7e-4a66-9dec-4c1536692a7c.jpg?v=1695858338&width=3840)
![Convertible Duffel Duffel Bags Knack](http://knackbags.com/cdn/shop/files/duffelexpanded_94ecfdec-4ce1-468a-9e89-04cab8e1fa75.jpg?v=1695858338&width=3840)
![Convertible Duffel Duffel Bags Knack](http://knackbags.com/cdn/shop/files/duffelinternalpockets.jpg?v=1695858338&width=3840)
![Convertible Duffel Duffel Bags Knack](http://knackbags.com/cdn/shop/files/duffelsuitcase.jpg?v=1695858338&width=3840)
![Convertible Duffel Duffel Bags Knack](http://knackbags.com/cdn/shop/files/duffmod.jpg?v=1695871532&width=3840)
![Convertible Duffel Duffel Bags Knack](http://knackbags.com/cdn/shop/files/duffelmodel1.jpg?v=1695871536&width=3840)
![Convertible Duffel Duffel Bags Knack](http://knackbags.com/cdn/shop/files/duffellaptop.jpg?v=1695858338&width=3840)
![Convertible Duffel Duffel Bags Knack](http://knackbags.com/cdn/shop/files/duffeltrolley.jpg?v=1695858338&width=3840)
Product Details
Dimensions
Volume
Weight
Material
How to live a One Bag life
![Office, Gym, and Travel in One Bag](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_officeGymTravel.jpg?v=1715638074)
Office, Gym, and Travel in One Bag
Everyday organization and large carrying capacity for whatever the day holds.
![Office, Gym, and Travel in One Bag](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_officeGymTravel.jpg?v=1715638074)
![Organized for work](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_organizeForWork.jpg?v=1715638074)
Organized for work
Protective fleece-lined tablet pocket, mesh zip organization pockets, & elastic loops for cords and pens.
![Organized for work](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_organizeForWork.jpg?v=1715638074)
![Expand your horizons](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_expandYourHorizons.jpg?v=1715638074)
Expand your horizons
Our patent-pending, hidden expansion compartment is the secret sauce that makes the Convertible Duffel perfect for living a One Bag Life. Simply unzip and expand the main compartment of this expandable duffel bag to get over 67% more carrying capacity. Unexpanded: 24 Liters. Expanded: 40 Liters.
![Expand your horizons](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_expandYourHorizons.jpg?v=1715638074)
![Switch it up](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_switchItUp.jpg?v=1715638074)
Switch it up
Backpack or Duffel? The choice is yours. When you want to change from a backpack to a duffel bag, simply unclip the shoulder straps, and tuck them away in the zip back panel pocket, attach the shoulder strap, and voilà, a great duffel!
![Switch it up](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_switchItUp.jpg?v=1715638074)
![Be Prepared](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_bePrepared.jpg?v=1715638074)
Be Prepared
It should never happen, but if that flight attendant makes you check your Convertible Duffel, don’t worry about your straps getting caught on the luggage carousel. Simply unclip your straps and stow them out of the way in the back panel pocket.
![Be Prepared](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_bePrepared.jpg?v=1715638074)
![Stay Connected](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_stayConnected.jpg?v=1715638074)
Stay Connected
Use the Convertible Duffel’s padded side computer pocket to always keep your laptop with you. The pocket fits 15” laptops (measured diagonally) and its suspended bottom helps keep your computer safely off the floor whenever you put your laptop duffel bag down.
![Stay Connected](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_stayConnected.jpg?v=1715638074)
![Bring your shades](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_bringYourShades.jpg?v=1715638074)
Bring your shades
The fleece-lined, sunglasses pocket is designed for easy access and protection. And there’s a bonus pocket behind it for other items (phone anyone?) that you need at a minute’s notice.
![Bring your shades](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_bringYourShades.jpg?v=1715638074)
![Don't look like a hiker](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_dontLookLikeAHiker.jpg?v=1715638074)
Don't look like a hiker
Only you will know that the sleek, hidden, zip side water bottle pocket holds your 25 oz S'well™/ 32 oz Hydro Flask™ bottles/ 20 oz Knack Insulated bottle.
![Don't look like a hiker](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_dontLookLikeAHiker.jpg?v=1715638074)
![Be discreet](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_beDiscreet.jpg?v=1715638074)
Be discreet
We’d love to tell you the location of the secret zip pocket for valuables, but then it wouldn’t be a secret.
![Be discreet](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_beDiscreet.jpg?v=1715638074)
![Stay Flexible](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_stayFlexible.jpg?v=1715638074)
Stay Flexible
Our adjustable sternum strap does a great job of distributing weight when you’re in backpack mode. But if you prefer a cleaner look, the strap unhooks for easy removal.
![Stay Flexible](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_stayFlexible.jpg?v=1715638074)
![Be Compatible](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_beCompatible.jpg?v=1715638074)
Be Compatible
Sometimes, your trips require a big piece of wheeled luggage. Don’t worry, it’s easy to bring your Convertible Duffel along too. Our hidden trolley sleeve lets you slip your Duffel over the handle of almost all sizes of wheeled luggage.
![Be Compatible](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_beCompatible.jpg?v=1715638074)
![Lock On](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_lockOn.jpg?v=1715638074)
Lock On
Keep everything secure during your journeys with lockable zippers on the main compartment. (Lock not included)
![Lock On](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_lockOn.jpg?v=1715638074)
![Stay dry](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_stayDry.jpg?v=1715638074)
Stay dry
While we don’t recommend swimming with your Convertible Duffel, our specially coated fabric and reverse coil zippers help keep your belongings dry in all types of weather.
![Stay dry](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_stayDry.jpg?v=1715638074)
![Smell Fresh](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_smellFrehs.jpg?v=1715638074)
Smell Fresh
Our custom-designed lining has a special antimicrobial treatment that helps to keep your Convertible Duffel fresh even when it’s filled with dirty or sweaty clothes.
![Smell Fresh](https://cdn.shopify.com/s/files/1/0023/8767/3149/files/duffel_smellFrehs.jpg?v=1715638074)