Osprey ultralight drysack 3made from silicone ripstop nylon this ospreys ultralight drysack is designed to keep your gear protected no matter how wet it gets equipped with a fully waterproof roll top closure coated fabric and taped seams to ensure that your gear stays dry in all conditions unlike other drysacks they have a rectangular shape which results in efficient packing when removed from your backpack theyre able to stand unaided featuresreflective graphic printinghigh visibilityf