HydraHike hydration is comfortable convenient and made for all adventures. Main compartment is accessible through top zipper. Made of lightweight ripstop fabric. Insulated reservoir pocket and 2-liter wide slide reservoir. BPA-free reservoir has bite valve with on/off switch. 360-Degree reflectivity. Front accessory pocket with organizer. Adjustable waist belt. Exterior daisy chain for attaching gear. 4-Liter total volume. Dimensions: 17.7" x 11.4" x 10".