The ALPS Mountaineering Tour boasts a roll top design which allows the pack volume to easily expand from 35L to 45L. Its lightweight 200D nylon double ripstop fabrics with 3D mesh suspension and aluminum stay provide a comfortable fit and carry. If you prefer no waist belt on a particular outing, the waist belt can quickly and easily be removed. The large main compartment, hip belt pockets and zippered lid pocket give the Peak 45 a total of 2,135-2,746 cubic inches of storage.Specifications and Features: Lightweight 200D nylon double ripstop fabric Roll top allows pack volume to expand from 35L to 45L Two side zippers provide access to the main compartment 3D mesh suspension Trekking pole loops Side and bottom compression straps Load lifter straps Removable waist belt with pockets Removable sternum strap Front zipper pocket Two stretch bottle pockets Aluminum frame stay Hydration compatible Rain cover is neatly stowed in a zippered pocket on the bottom of the pack until needed Pairs well with Reservoir 3.0