Consisting of an extremely fine mesh material bound to a durable elastic ring, the skimmer sock prevents debris, hair, grass, leaves, scum, pine needles, pollen and bugs from clogging the filter system. The filter sock fits most skimmer baskets like a glove. Elastic band holds them tight on the edge to catch small debris that would clog up the pump or filter. This allows your filter to run a little longer between cleanings. Makes filter cartridge cleaning much easier and a lot less messy. When soiled, just toss it... or spray with a garden hose. Each can be reused several times, if desired. Fits any shape skimmer basket.