TRUA(R) Zip closure delivers an immersion-ready waterproof seal; the toothless "zipper" is self-repairing, making wilderness maintenance a non-issue. Heavy-duty UV and wear-resistant PVC-free material with RF welded seams can handle the wear and tear of any outdoor adventure, season after season. Stackable flat-base design makes packing, storing and rigging easy. Two compression straps reduce bag size and stabilize gear. Larger duffels feature a removable padded shoulder strap and end handles for easy hauling. 12L duffel features a removable unpadded carry strap. Expedition DriDuffels have an IPX7 Rating, meaning when zipped, contents inside the duffle are protected against water immersion for 30 minutes up to 1 meter deep. Note: To reduce a potential unwanted opening, remove excess air inside the duffel before fully sealing the TRU Zip closure. Once the bag is loaded, leave a small opening at the zipper before fully closing. Press down on the bag to form the material around the contents as tight as possible, allowing air to release before fully closing.