The minimalist GravityWorks 2.0L Bottle Kit system is both ultralight and ultracompact, thanks to a simple adapter that easily connects the pump-free water filter system directly to a water bottle or hydration reservoir, conveniently filtering water for 1-4 people in the backcountry. Bottle Kit: Minimalist setup uses a Universal Bottle Adapter to connect the system directly to an existing water bottle or reservoir*. No pumping: Just fill the dirty reservoir, hang it, and let gravity do the hard work. Fast: Filters up to 1.5 liters per minute; filter lifetime up to 1,500 liters of water. Effective: Meets all EPA & NSF guidelines for the removal of 99.9999% of bacteria and 99.9% of protozoa**. Ultralight & Ultracompact: System can weigh as little as 6.6 oz. (187 g) and stows smaller than most 1L bottles. Field-cleanable: Microfilter can be easily backflushed in 4 seconds to maintain filter performance. Hollow Fiber Advantage: Hundreds of tiny, hollow fibers, enable the microfilter to filter water faster than traditional filter media. Easy collecting & dispensing: Collecting water is easy—simply open the top, scoop water, and close; control delivery of filtered water with hose shutoff clamp. Comes with: 2.0L Dirty reservoir, Hollow Fiber microfilter, Universal Bottle Adapter, hoses, storage sack. *Adapter interfaces with all Platypus bottles and most from MSR, Nalgene, Klean Kanteen, CamelBak and many more (these trademarks are not owned by Cascade Designs, Inc.). **This includes Giardia, Cryptosporidium, E. coli, Salmonella and Cholera. Made in U.S.A. of U.S. and Imported Materials.