Usage Tips:[Fitment]- Aquarium Bio Sponge Foam Filter Pads Replacement Compatible with for FX4, FX5, FX6 Canister Filters [Range of Application]- for Fx4 Foam Filter Pads are suitable for both freshwater and marine aquariums [Fuction]- These pre-filter sponges capture micro-particles as the water passes through. Provides efficient water flow with less clogging for long lasting filtration. Provide filtered water which results in the Healthy environment to our [Contains 12 Pcs Foam Filter Pads]- Filter sponges needs to be replaced after 6-12 months due to micro-holes of sponge gradually clog by debris, That's when the sponge filter starts to lose its efficiency, they need to be replaced [Easy to Use]- Easy to install and directly Fit, Save your time and money. This is non-aftermarket part, but can Perfect match and work Color: White Material: Sponge Package Contents: 12 x Fx4 Foam Filter Pads Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.