soclean replacement cartridge filter kit for soclean 2 go travel machines, includes filter cartridge and check valve, genuine oem with full warranty soclean this cartridge filter kit includes one replacement filter with o-ring attached and one replacement check valve for soclean 2 go travel machines. the filter and check valve should be replaced every six months. <br><br> only filter kits purchased from seller "soclean" can be guaranteed authentic, and are tested and sold by the manufacturer of the soclean 2 go.