ExtremeMist® PSS Waist-Pack provides easy access to your gear and hydration bottles. Designed with convenience in mind, it zips to the bottom of the "Portable Sanitizing System". When zipped to the pack, it redistributes much of the weight from your shoulders to your hips. It has a large back Zippered compartment with key clip, bungee attachment, 2 roomy side zippered pockets, dual hydration bottle holders, and a mesh back panel for a comfortable fit. Use as a standalone hydration pack, or as an attached accessory. 2 fully expandable sizes, Small fits from XXS - Med, Large, fits up to XXXXL.