Material: Cotton, Color: White, Size: about 38x12x2cm (LxWxH), Excellent water permeability.It suitable for use in outdoor pond filtration systems as well as indoor tanks, any filters, sump and aquariums. Effective Fish Tank Filter Media - Provide both mechanical and biological filteration, perfect for freshwater or saltwater aquariums reef tank, making your fish tank water super clean and clear. Place our aquarium sponge filter pad traps micro and macro organic particles, foreign debris, waste, excess fish food, decaying plants, detritus, and other coarse helps maintain beautiful water for sustained enjoyment and longevity of your fishes According to the analysis of the experts, products with this pore gap and flexibility. The most suitable for cultivating the fine nitro bacteria. And also improve water quality than will reduce death rate of fishes in tank