Ultimate Duo Exterior Filter - Equipped with garden hose fittings to install outside of RV/Boat to water hose. Cartridges #7 & #5 are included with housing wrench. Tested to remove 99.9% cryptosporidium and giardia cysts, reduces bacteria, sediment, chlorine and unpleasant taste & odors. Flow rate 2.5 GPM. Comes pre assembled.