Culligan EZ-Change Water Filter Replacement Cartridge. Clear, clean, great-tasting water for drinking and cooking is easier to achieve than ever before. The Culligan(TM) RC-EZ-4 Level 4 Premium Filtration replacement cartridge reduces bad taste & odor, aesthetic chlorine taste & odor, sediment, lead, cysts such as giardia & cryptosporidium, mercury, turbidity, particulate Class I, VOC’s, MTBE and chloramines. Installation is easy with twist-on, twist-off design mechanism. This filter can be used in the following Culligan(TM) models; US-EZ-1, US-EZ-3, US-EZ-4, IC-EZ-1, IC-EZ-3, IC-EZ-4, and RV-EZ-3. The cartridge has a life of up to 6 months or 500-gallon capacity.