The USWE Outlander XC 4L is a lightweight hydration pack built for cross-country mountain biking and gravel riding - enough room for a jacket, tube and snacks without the bulk of a trail pack. No Dancing Monkey(TM) 4-point harness - USWE&';s patented bounce-free suspension that snugs tight without restricting breathing 4L total pack volume with a 1.5L Elite hydration bladder included Breathable back panel and lightweight front straps for long, hot rides One-click buckle for one-handed on/off Activity: XC mountain biking, gravel, marathon racing