Compatible with 108oz/3.2L and 67oz/2L stainless steel cat water fountain models, including PLWF003. Replace the carbon filter every 4 weeks; during hot weather, replace every 2 weeks to maintain water quality. Replace the foam filter every two months to ensure fresh water. This set includes 8 filters and 8 sponges for easy replacement and enhanced pet protection. Three-layer filtration system: pre-filter traps hair and debris, middle layer reduces residual heavy metals, and final stage promotes healthier, high-quality flowing water for pets to drink clean water all day. Before use, soak the filter in a clean bowl of water for 5 minutes to fully saturate. Do not install dry or soak directly in the fountain tank to prevent overflow and ensure proper function. Filter material: sponge. Color: white and black. Package contents: 8 x filter elements, 8 x filter sponges. Product does not include other items not listed. Note: Lighting and display differences may cause slight color variation between image and actual item. Measurement tolerance: +/- 1-3 cm.