[DETAIL] Features: This sponge is an accessory for fish tank filter. Using environmental high density sponge filter,can absorb dirt,quickly resolve fish feces and eliminate smell in water. Combined air pump using,can improve water oxygen level,achieve oxygenation and bio-filtration double effect, keep water clean. 3 size can be available for you to choose and high density makes great effective filter effect. Specification: Material: Bio-Sponge Type: Fish Tank Filter Media Color: Black Size: S,M,L Shape: Square, Round Quantity: 2 Pcs / 6 Pcs Note: 1.Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package includes 2 / 6 x Sponge [ATTRIBUTES] - Hign-concerned Chemical: None - Voltage: none - Type: fish - Hign-concerned Chemical: None - Voltage: none - Type: fish - Origin: Mainland China - Power (W): None