A great all around mountain biking, trail running, and day hiking pack, the Osprey Viper 9 hydration pack keeps you well hydrated while offering comfortable, organized gear storage. AirScape backpanel with perforated foam offers lightweight support and great ventilation to keep you cool and comfortable. BioStretch harness offers full range of motion adjustable sternum strap features a built in magnet for bite valve attachment. Detachable 20 mm webbing hipbelt features a modified ErgoPull system for quick, easy fit adjustments. Dual zippered panel load access to the main compartment makes it super easy to pack your gear in the morning and find it later sleeves and mesh pockets inside help keep bike tools organized. Patent pending LidLock helmet attachment system provides an easy solution for keeping your helmet secure and out of the way. HydraLock compartment keeps your 3 L HydraForm reservoir included secure and separated from the rest of your gear. Top zippered slash pocket is lined with heat embossed fabric to protect your sunglasses, phone, mp3 player, or GPS. Versatile front shove it pocket lets you quickly stash extra gear. Integrated blinker light attachment patch on the front of the pack adds extra visibility on night rides or runs.