This convenient pouch fits seamlessly with the TrailBuddy, TrailBeast and on your bicycle cockpit. It's snug enough to holder a standard riding water bottle and spacious enough to hold a full sized Nalgene! With a few velcro straps it easily moves between your bike and you TrailBuddy. The strap placement allows for secure placement on both. It can double as an accessory pouch for cameras, snacks or miscellaneous junk you probably could do with out. *TrailBeast not included...or the bike either.