UPGRADED BUCKLE STRAP: keep backpack rain cover in position, Prevent backpack cover from sliding off. FOR 40-50L BACKPACK: Length(9.8-13.7"), Width(5.9-9.8"), Height(21.6-25.5") HIGH-LEVEL WATERPROOF: Our backpack cover is made of 210t TAFFETA mixed material features wear-resisting and durable, support 10000 mm water pressure. 4-LAYER CONSTRUCTION:...