Features of the Sea to Summit 20L Ultra Sil Dry Bag Non-wicking hypalon roll-top closure with patented field repair buckle High-Performance bluesign Approved Ultra-Sil 30D Cordura nylon fabric Semi-translucent fabric makes it easy to identify contents Oval base prevents rolling and packs efficiently Slippery finish slides into tight spaces in your pack or bag Cordura brand yarn is a High-tenacity nylon yarn that&';s stronger and more abrasion resistant than standard nylon fibres of the same weight Proprietary Ultra-Sil fabric employs Corudra High-tenacity nylon yarn for increased strength and abrasion resistance Ultra-Sil Dry Sacks, the 30D High-tenacity nylon outer face is impregnated with silicone and a Polyurethane (PU) coating is applied on the inside Water resistance of over 2,000mm Silicone outer face sheds water exceptionally well and creates a slippery surface for easy packing PU coating on the inside improves the waterhead rating and allows for sealing of the seams.