JUWEL Poly Pad is used to catch coarse particles of dirt in the water. As a mechanical pre-filter, it protects the filter from rapid soiling and means that you don't have to clean the other filter media as often. JUWEL filter floss consists of fine, residue-free polyester material and is suitable for use in both saltwater and freshwater aquariums. It comes in three sizes, in packages of up to 5. Characteristics of JUWEL Poly pad: Serves as a mechanical pre-filter Protects other filter media from rapid soiling Made of residue-free polyester material Suitable for use in saltwater and freshwater aquariums 5 filter flosses in each package SIZES: Medium (9.5 x 9.5cm) Large (12.5 x 12.5cm) Xlarge (15 x 15cm)Ę