We were the first company to introduce a compression dry sack without a purge valve. Air permeable e VentA(R) fabric on the base allows air to be pushed out of the sack, while stopping water getting in: lighter, simpler and more reliable than a purge valve. The body is made of a tough 70D polyurethane coated Nylon. It has a non-wicking roll-top closure and a lid with four straps for even compression. Specifications. a 10,000mm waterhead, rugged 70D Nylon body and lid. a Double stitched and tape sealed seams. a Non-wicking roll-top closure with lid. a Bar tack reinforced stress points. a White interior for better visibility of contents. a Pull handle on the bottom. a Includes Field Repair Buckle. a Size: 8&';&';x18&';&';. a Weight: 5.2 oz / 148g. a Max/Min: 14L to 4.5L.