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 a silver cannister (Replacement Part Code - SSC10 {702}). Comes with 1/2" BSP fittings. This unit uses the 'Alternative' sanitisation medium.