Description XINYOU BIO FILTER BIOCHEMICAL MAT (50*50*3.8CM) BLUE Specifications: Core Components: SPONGE Color: Blue Application: Filtration Usage: Filter Function: Remove Impurities Size: 50*50*3.8cm Features: 1. Suitable for marine, freshwater and planted aquariums 2. High-density and soft materials guarantee efficiency 3. Dissolves waste, improves water quality, reduces fish’s death rate 4. Rinse with aquarium water or chlorine-free water