The osprey viper 13 hydration pack is completely trail ready with a ventilated airscape backpanel lidlock helmet attachment and 25l hydraulics lt reservoir compatible as well as boasting all of the active features expected from a hydration pack the viper 13 also features a large capacity across several pockets for maximum load balanceactivityrunning cyclingadjustable back systemnocolour swatchblackgenderunisexhydration compatibleyeslaptop compatiblenpocket details1 x harness stretc