FUNCTIONAL: Comes with two independent compartments for snacks, tissues, phones, etc. INSULATED: Comes with an extra insulated 2 Liter bladder compartment. ADJUSTABLE: Fully adjustable shoulder and chest straps that will fit chest sizes from 26 inch – 52 inch to guarantee the perfect fit, keeping the pack from bouncing while running. COMFORT: Designed with a unique padded back section to allow airflow between your back and the pack PRACTICAL: Light as feather. You don't even know notice there is something on your back! DURABLE: Extremely durable polyester/nylon material that is water proof. FASHIONABLE: Beautiful luminescent silver color PERFECT SIZE: Backpack size is 11" x 3.5" x 16" (28 x 9 x 41cm), with a 2 Liter water pack. USE ANYWHERE! Hydration pack is great for Raving, Cycling, Running, Hiking, Festivals, & More!