Waterdrop WD-G2CF Filter, replacement for WD-G2-B, WD-G2-W, WD-G2P600-W Reverse Osmosis System, 12-month Lifetime. The 2-in-1 composite filter uses a natural activated carbon block and a sediment PP membrane, which effectively reduces sand, rust, particulates, suspended solids, and other impurities, providing you with clean and pure water. The filter provides you with 12-months or 1,100 Gal. of clean filtered water. To get the best filtered water, please replace the filter according to the replacement cycle.