The ZooBest filter net bags (filter stockings) are made from unrotable synthetic fibres for recepting of active filter coal, secial filter coal, black peat granulate, peat fibres, phospahte removers, exchanger granulates and many others. Super elastic !ZooBest Filter Net Bag:-Size S, Dimensions: approx. 5x9 cm, net size: very fine, white-Size M, Dimensions: approx. 10x23 cm, net size: very fine, white-Size ML, Dimensions: approx. 13x35 cm, net size: medium, white-Size L, Dimensions: approx. 12x50 cm, net size: rough, green--Size XL, Dimensions: approx. 35x58 cm, net size: rough, green-Size XXL, Dimensions: approx. 35x75 cm, net size: rough, white