The Stuff Sack is made from a durable 70D recycled Nylon and is the perfect solution for organized modular packing on any adventure. A white interior coating helps to shed moisture and makes finding your contents easy. The unique tear-proof drawcord top with Capture Cord Lock opening is easy to use. These tough Nylon Stuff Sacks do not have taped seams or a roll-top closure; so they are water resistant rather than waterproof.