The Sea to Summit Lightweight Dry Sacks offers durability & reliable weather proofing for the items that you need to protect from the elements How to use 1 Any roll-top dry sack must be closed properly to ensure water can t get in Begin by folding the Hypalon reg strip down first & be sure to have at least three rolls before closing the buckle 2 Avoid contact with sharp objects or subjecting the sack to high abrasion as this could compromise the waterproof fabric 3 Like all manufacturers of roll-top fabric dry sacks Sea to Summit recommends that sensitive electronic devices be double bagged i e putting electronics inside one dry sack then placing this inside a second dry sack For maximum protection the use of a waterproof hard case should be considered 4 Not intended for situations where dry sack will be submerged under water