With its 22 liters of compressible cargo storage and a 2 liter water reservoir, the American Outback Flash Pack is a versatile multi-sport reliable partner Perfect for short trips, long runs, and daily commutes, designed to carry a lot of gear and be prepared during trekking. No matter where you go, the Flash Pack has you covered QUALITY CONSTRUCTION AND DESIGN: Cushioned breathable mesh back panel. Water drop holes for quick drainage Padded for maximum comfortLIGHT AS A FEATHER (20 oz): Designed for comfort, the hydration pack is ultra-lightweight, streamlined and easily adjustable. Fully adjustable shoulder/chest strapHYDRATION BLADDER INCLUDED: 2 Liter (.5 Gallon) PVC & BPA Free Bladder: Twist-free tube with soft high-flow bite valve and easy one-handed shut-off buttonFeatures: Hidden side pocket holds water bottles and other trail essentials. Easily attach trekking poles to the front of the pack and two attachment loops at the bottom. The safety whistle is easily accessible to the chest strap