Head out for a quick after work run, hike, or bike ride with the minimalist Camelbak Hydrobak Hydration Backpack. This lightweight pack carries a 50 ounce Antidote reservoir to keep your fluid levels up over the course of a 1. 5 hour ride while its external fill reservoir opens wide, closes with a snap, and lets you reload water without unloading your pack. Designed with an air mesh back panel, mesh harness, and a short torso fit, the Hydrobak sits above your jersey pockets and helps keep you cool and comfortable on the trail. A small external pocket holds your cell, indispensable multi tool, or energy goo while reflectivity features allow others to spot you in low light conditions.