Keep water crisp, clean, and pump-friendly with our 4-pack of replacement filters for the Vet-Approved Stainless Steel Cat Water Fountain – 74oz. A triple-layer design (cotton mesh + ion-exchange resin + activated carbon) traps hair and debris, reduces limescale and odors, and helps protect the pump. Each filter lasts up to 2 weeks (one pack covers up to 8 weeks for one cat). BPA-free; rinse before use. Compatible only with the 74 oz Scratching Cactus stainless steel fountain.