Absorbent Sponge is well-made of for durable and practical use. It can be used in seawater tank, fresh water tank, aqua-plant tank. And its strong filter ability can stable water quality and reduce fish died. It can be freely cut. High density, can filter impurities in the water when placed in the tank, and can also maintain the humidity in the tank. Features -Color:Yellow -Material:Sponge -Size:16.50X10.00X2.00cm/6.48X3.93X0.79in -High water permeable feature and filter effectively. Adsorbent Sponge can give you a . -Easy to clean. Machine washable. No deformation. You can use it with confidence. -Great fish tank and Aquarium Filter Cotton and give the fish fresh environment. -The use of environmentally friendly materials, super toughness and resistance to pressure. -Suitable for aquaponics systems, turtle tanks, terrariums, and much more. It is very useful. Package list: 10 x Sponges