Pur RF99991 3 Stage Faucet Mount Filter 1Pack PUR Ultimate threestage filter represents a new standard of excellence in water filtration. Compatible with all PUR faucet mounted filter systems including horizontal and vertical styles plus and ultimate and all colors and finishes. Threestage filter removes 99.9 percent of bacteria from faucet water therefore improving its taste and eliminating odors. Uses ionexchange resin and activated carbon to remove impurities and harmful elements from your water. Filters up to 100 gallons of water with a life span of approximately two to three months. Electronic indicator tells you when it is time to replace filter. One filter provided.