Compatible with 108oz/3.2L and 67oz/2L Stainless Steel Cat Water Fountain. Also compatible with model PLWF003. Replace the carbon filter every 4 weeks; in hot weather, replace every 2 weeks to prevent bacterial growth. Replace the foam filter every 2 months to maintain fresh water. This set includes 8 carbon filters and 8 foam sponges for easy replacement and extended protection for your pet. Three-layer filtration system: Pre-filter traps hair and debris; activated carbon filter reduces chlorine, odors, and heavy metals; fine foam filter ensures cleaner, healthier flowing water for pets to drink clean, fresh water all day. Before use, soak the filter in clean water for 5 minutes to ensure proper saturation. Do not install dry. Never soak the filter directly in the fountain reservoir to avoid dust contamination. Material: Sponge Color: White + Black Package Contents: 8 x Carbon Filters, 8 x Foam Sponges Note: Only the items listed are included. Other accessories shown are not part of the package. Lighting and monitor settings may cause slight color variations between the image and actual product. Measurement tolerance: +/- 1-3 cm.