These fully tested waterproof stuff bags have a roll top closure which also acts as a compression system squeezing air out of the bag as you roll down 7 sizes and a multipack are available and each size is colour coded ideal for using inside or outside a rucksack or as a full rucksack linerfeatures9679 30 denier siliconised cordura9679 fully taped seams9679 roll top closure with single click shut buckle9679 seven sizes 405 10 15 25 40 70 and 100 litres41 and multipack 40