30 premium nylon skimmer socks per pack. Ultra-fine mesh blocks the finest debris (leaves, hair, pine needles, insects, etc.). UNIVERSAL: Ultra-fine mesh is flexible and adapts to all shapes of skimmers available on the market. QUALITY: The pool skimmer pre-filter basket meets the highest quality standards to prevent debris and chlorine from entering the water. EASY INSTALLATION: The sock can be installed in seconds. Replace every 4 to 8 weeks. Filter socks are recommended to protect pool pumps from residue that slows down or impedes water circulation.