Compatible with 108oz/3.2L and 67oz/2L Stainless Steel Cat Water Fountain. Additional compatible models include: PLWF003. Replace the carbon filter every 4 weeks; in hot weather, replace every 2 weeks to maintain water quality. Replace the foam filter every 2 months to keep water fresh. This set includes 8 carbon filters and 8 foam sponges for easy replacement and extended protection for your pet. Three-layer filtration system: - First layer: Blocks hair and debris - Middle layer: Reduces residual heavy metals - Third layer: Promotes healthier, high-quality flowing water, ensuring pets drink clean, fresh water all day Before use, soak the filter in a clean bowl of water for 5 minutes. The filter must be fully soaked before turning on the fountain; otherwise, water may not flow properly and could cause overflow. Do not soak the filter in the fountain tank to avoid dust contamination. Material: Sponge Color: White + Black Package Contents: 8 x filter elements, 8 x filter sponges Note: Only the items listed are included. Light and display differences may cause slight color variation between the image and actual product. Measurement error is +/- 1-3 cm.