This Glacier Bay refrigerator system installs directly to the external water line so it fits all major brands of refrigerators and ice-makers providing great tasting water and cleaner, clearer ice. Adapts easily to boats, RVs, campers and motor homes. It is NSF certified and reduces sediment, turbidity, chlorine taste and odour, cysts, lead, lindane and atrazine. The first 6-month filter (HCGREF5) is included with system purchase. When changing the filter on this system, there is no need to shutoff water supply allowing for an easy no mess filter change.