16PCS Aquarium Replacement Filter Pads for SUNSUN GRECH HW-304 HW404B

•  12x White Filter Pads
• 4x Blue Filter Pads
• 8.5" (L) x 8.5" (W) x 0.75" (H)  

This is the original filter pad sponge for SUNSUN/PERFECT/GRECH/ SUPERHW-304B, HW-404B AQUATOP CF-500 Canister filter 1.Provides both mechanical and biological filtration 2. Promotes nitrogen cycle reduce the death rate of fish 3. Can be used again after cleaning