1. MATERIAL -- Filter sponge is made of high quality Sponge, which is reusable and washable, can be used for a long time. Package includes 12PCS Filter Sponge. 2. SIZE -- Inner diameter of swimming pool filter sponge: 1.57inch/4cm, Outer diameter: 3.94inch/10cm; The length: 7.87inch/20cm. Filter sponge for type a 3. FEATURES -- Soft, not easy to deform, fast filtering speed; Good air permeability, Flexible, resistance, environmental protectio, foam sponge . 4. EASY TO USE -- The swimming pool filter foam is recommended to replace once a week, and these foams can be easily cleaned and replaced. It can work for about 2 months. 5. APPLICATION -- Filter sponge is suitable for Bubble & Jetted Pure-spas Swimming Pool, Baths, Fish Tank. Colour: Blue Material: PU Sponge Size: 100 x 200mm Package Contents: 12 x Blue Filter Sponge 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.