Great for everyone who already owns a pack, the CamelBak's UnBottle is a stand-alone system that easily slips into or attaches to any pack. The Unbottle features easy, convenient filling with external access to the Omega HYDROTANIUM Reservoir with lifetime warranty. The Slick Clips make attaching UnBottle on the outside of your pack a breeze, and being fully insulated it will keep liquid cool for hours. The Unbottle is made with lightweight, abrasion-resistant material.