Karrimor hydration bladder the karrimor hydration bladder is a great accessory for walking cycling and a mulitude of other outdoor activites the bladder will fit almost any hydration compatible rucksacks or hydration pack great for upgrading your back pack or replacing an aging drinks bladder constructed from hygenictpu material this hydration bladder has a large screw cap for easy filling and cleaning the bite valve also features a dust cover to keep the valve clean hydration bl