This filter sock is good for improving water quality and protect water system, and widely used in fountain, fish tank, gardening, water feature, fishing filtering.SpecificationColor: WhiteMaterial: Polypropylene PPDiameter: 10.5cm / 4''Overall Dimension: 23 x 14cm / 9 x 5.5'' (L*W)Package Content: 1 x Filter SockAdvantagesMade of sturdy material in good workmanship, solid construction and delicate sewing process, it is lightweight and soft, reusable and durable, easy to clean, pressure and impact resistance.InstructionEasy to use: put the filter sock on the skimmer basket, easy to filter most of stuff.NoticePlease kindly note that there will be 1-2cm tolerance of measurement.