Pre-Filter Oil Skimmer: Made of high quality durable nylon material with excellent elasticity, easy to stretch and not easy to damage or clog. A pack of 20 tablets is enough for long-term use. Size: 13.2 x 18.2 cm, stretchable up to 40 cm, the socks have good elasticity and can be easily stretched to cover the skimmer basket, suitable for most types of pool pumps, filter baskets, pool baskets or Wait filter baskets. Protect the filtration system: these oil skimmer socks protect pump failures and shaft seals from damage or blockage without worrying about those contaminants damaging your filter system and extending the life of your pool filter/filtration system. > Good Helper: Pool filter socks can help you maintain your swimming pool. These pool skimmer socks filter out oil, hair, bugs, grass, pollen, leaves, pine needles and other small debris that can clog your pool's filtration system. It's a simple, effective and inexpensive way to protect your pool filter. EASY TO INSTALL: These pool filter socks are stretchable. Just slide the sock over the basket and install it in seconds, it won't come off easily. It fits perfectly into the basket of your pool skimmer. Regular replacement of worn socks is sufficient.