Incredible effective surface area. ZOOX Next Generation Biomedia Light Standard 13.5 fl oz (400 ml) for both freshwater and saltwater. Features: This filter material has amazing penetration and water retention. It is an all-connected structure that allows all perforations of the surface area. With a maximum of 900 sq ft (900 sq m) per box, this product can provide the ideal bacteria. The porous space is perfect for securing bacteria, which provides strong support for aerobic bacteria. Made of a polymer material that is safe for bacteria and all organisms. There is no need to worry about fine dust or melting of filler materials, and it can be cleaned even when clogged after long-term use. It can maintain about 70% of bacteria after removing organic substances. Comes with a dedicated plastic net. Contents: 0.4 L (0.4 L) (Includes exclusive plastic net) Size (approximate): External Dimensions (W x D x H): 0.4 x 0.4 x 0.4 inches (1 x 1 x 1 cm) (When water passed), Material: Multi-layered polymers, Country of Origin: China