When youre squeezing in a quick ride after work, the Osprey Viper 3 Hydration Pack is the perfect size. The suspension is designed for moving light and fast: A foam framesheet spreads weight across a ventilated mesh backpanel for lightweight comfort. The BioStretch shoulder harness provides a contoured fit and the webbing hipbelt is removable to shave ounces. If you end up carrying extra weight, top compression straps lend extra load stability. Atilon foam framesheet allows dynamic body movement while it spreads the load across the entire backpanel. Backpanel is AirScape mesh covered ridged foam for maximum ventilation while keeping the load close to your body. BioStretch harness with mesh covered die cut foam for an active and contoured fit and ventilation soft, breathable spacer mesh contact surfaces. Removable 20mm webbing hipbelt helps to stabilize the load. Uper side compression straps. Direct access zip path to reservoir compartment. Front fabric shove it pocket with zip organization pocket. Lidlock helmet attachment. Blinker light attachment. Magnetic sternum strap bite valve attachment. Hydraulics LT 2.5L reservoir included.