The osprey viper 3 hydration pack houses a plentiful 25l hydraulics lt reservoir for comfortable reliable on the go hydration an airscape backpanel provides effective cooling with specially developed air channels to encourage breathability an asymmetric zip opening allows for quick and easy refillingactivityrunning cycling fitnesscolour swatchorangegenderunisexhydration compatibleyeslaptop compatiblenpocket detailsstretch harness pocket internal hydration sleeve internal organise