Dual RV Water Filtration Unit. Comes with a 5 micron carbon cartridge (Replacement Part Code - A-AC5 {420}), a 0.4 micron ceramic cartridge (Replacement Part Code - CF-4 {422}), a housing spanner, brackets and sanitisation devices (Silver Anode Replacement Part Code - SSA {701}). Comes with 1/2" BSP fittings. This unit uses the 'B.E.S.T.' electronic sanitisation medium.