The Camelbak MULE hydration backpack is a Camelbak classic. The MULE offers the ultimate combination of organized and overflow cargo options, including a new weather resistant MP3 pocket. With a durable splash guard that protects your pack from mud and abrasion, you can head off into any terrain. For those of you heading for a long hike or bike ride, the 100oz of water will keep you going on the trail.