Sea to Summit Ultra-SIL Dry Sack - Orange 4L nylon Super compact and ultra lightweight Made of Ultra-Sil nylon, a polyurethane coated siliconized Cordura for ultimate waterproofing and maximum durability Non-wicking Hypalon roll top closure with stiffener at the top for a better seal Soft and flexible with a slippery finish for easy packing Translucent fabric allows good visibility of the contents