Lifeunion Ultimate Hydration Pack Bladder for Hunting Hiking Climbing, 2.5 L Bladder Capacity, Adjustable Shoulder Strap & Emergency Carry Handle nylon Importado Measures:18.5"*10"*0.98" It is made from 600D waterproof nylon,this is durable and elastic material Equipped with a tube with a bite valve to drink, so you don't need to hold it to drink Two layers cargo design, one for hydration bladder, and the other for extra carrying purpose Adjustable shoulder strap and chest belt, suitable for heavy carrying,perfect for hiking, climbing, riding and other outdoor activties