The 3D Hydro 2 L Reservoir from Gregory is a hydration system for hiking and training. 3D Hydro has a magnetic nozzle that keeps the nozzle in place during the hike. When you want to dry the bladder, you simply hang it by the built-in hook. Gregory 3D Hydro 2 L Reservoir Optic Blue | Buy Gregory 3D Hydro 2 L Reservoir Optic Blue here | Outnorth