Black Label Society Bison Dry BackpackThe Dry Backpack by Bison Coolers was designed to keep your gear dry and protected no matter what kind of wet and wild adventure you take it on. It's constructed from Marine Grade TPU materials with sonic welded seams to create a waterproof shell thats also tough.. really tough. The heavy duty water resistant zippers are designed to keep water out and feature over sized T pulls for easier opening and closing. Our backpack straps give maximum comfort