Ledge Sports Karate Monkey Hydration Pack Lightweight Hydration Pack, Breathable Design Adjustable from Small Children to Adult Extremely Durable Design, Rip-stop Material.Lightweight and Adjustable for Children to Adult, Includes 1.5 Liter Bladder and is Compatible with Jetflow Bottle Hydration System 1.5 Liter Bladder Included (Fits 2.0 Liter) Jetflow Manifold Compatible