Ultra tough, comes in 3 sizes Concerned about bladder failure out in the backcountry? If so, you'll appreciate the rugged character of MSR's Hydromedary System. The Hydromedaries are slimmed-down offshoots of our Dromedary Bag, designed to fit into your current hydration pack or backpack. Made from lightweight but incredibly tough 200-denier nylon lined with food-grade polyurethane, the Hydromedary bags are the strongest hydration system available. The high-capacity, 40-inch drinking tube will stay soft and flexible even in freezing temperatures. MSR Bullet Bite Valve prevents leaking. 360° swivel elbow prevents kinked hoses and impaired water flow. Compatible with MSR: - Waterworks & Miniworks Filters, MSR shower kit, MSR Spigot Cap.