Whether you're trail running or endurance racing, Osprey's Rev 18 packs everything you need to go far. Its Biostretch harness and hipbelt move with you during high activity endeavors, offering stability and comfort. A 2.5-liter Hydraulics LT Reservoir ensures you are properly hydrated while harness pockets store an extra water bottle and food so you can refuel on the go. The main compartment and outside bungee cord allow you to store extra layers so you're ready for unpredictable weather. And, the Rev 18 features a sunglass pocket, side mesh pockets, hipbelt pockets, and an easy-to-access DigiFlip pocket for your phone.