[Fitment] - Aquarium Bio Sponge Foam Filter Pads Replacement Compatible with FX4, FX5, FX6 Canister Filters [Range of Application] - Fx4 Foam Filter Pads are suitable for both freshwater and marine aquariums [Function] - These pre-filter sponges capture micro-particles as the water passes through. Provides efficient water flow with less clogging for long lasting filtration. Provides filtered water which results in a healthy environment [Contains 12 Pcs Foam Filter Pads] - Filter sponges need to be replaced after 6-12 months due to micro-holes of sponge gradually clogging from debris. When the sponge filter starts to lose its efficiency, it should be replaced [Easy to Use] - Easy to install and direct fit. Saves time and money. This is a non-original aftermarket part that can perfectly match and function properly 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 to be slightly different from the actual item. Measurement allows an error of +/- 1-3 cm