Sea To Summit Tpu Guide Waterproof Accessory Case nylon Totally welded construction - no stitching, Welded seams, die cut anchor points Freeze Proof - Will not crack in extreme cold, High strength, PVC free TPU material A touch-screen device will work while inside the case! Watertight triple-fold Velcro closure, Flexible and crease resistant Convenient neck strap included As an airproof barrier in our Air-Sprung Cell and Self-Inflating mats. Here it is used in a liquid-extruded format  the TPU bonds to the face fabric for the highest possible level of reliability. As a waterproof barrier in our Accessory Guide Cases and Map Cases; and in several models of our Dry Sacks. Here it is used in a film format, where its superior flexibility (even in cold weather) and waterproofness are key. As a waterproof barrier in the Nylon Folding Bucket. This particular film is also food grade  ideal for water storage. As a transparent window in View Dry Sacks and Travelling Light products  allowing you (and TSA inspectors) to see the contents.