The ortlieb x tremer backpack is a fully waterproof dry bag which is ideal for trekking and touring purposes the large waterproof expedition dry bag with roll closure is available in two sizes and takes up huge amounts of equipment it is also very suitable as protective cover for trekking rucksacks during transport on planes trains boats or four wheel vehicles the x tremer is the flexible alternative to rigid transport barrels the 100 waterproof x tremer features a rolln snap closure an