The Platypus GravityWorks Pump-Free Water Filtration System delivers fast, pump-free performance with even less weight and more ease. Using advanced, Hollow Fiber technology and a little physics, the Platypus GravityWorks allows you to collect, transport, filter and dispense water, easier and faster than any other system available. An all new filter housing and streamlined Clean reservoir shave two ounces off an already wickedly light filtration system, and a straightforward, modular design presents customizable options for further trimming weight on ultralight journeys.