Osprey's Viper 5 is a minimalist hydration pack. Lightweight and durable, it's made from triple ripstop polyester material and has an easy to access, 2-liter Hydraulics reservoir. For storage, there's a main compartment with pockets for your tools, a Shove-It Pocket for a jacket, and Osprey's LidLock helmet clip. Other features that will have you singing this pack's praise include a comfy BioStretch harness, a removable webbing hipbelt, a ventilated back panel, and a magnetic bite valve that stays put no matter how rough the trail gets.
Viper and Verve Series ~ Osprey Hydraulics
Osprey LidLock Tech Video