Material: the pool skimmer socks are made of good quality nylon fabric, and the package includes 20 pieces, enough for your application for a long lasting time Size: 21.5 x 12cm / 8.46 x 4.7 inch (LW), and the socks have good elasticity to stretch easily and enough to cover the skimmer basket, suitable for swimming pools Function: the filter layers like a net to filter garbage such as leaves, grass, hair, scum and so on, help keep your swimming pool clean and save cost Warm notice: Most often, the socks can be applied for 4-8 weeks with its good effect, please clean them to apply again or throw them away when soiled Good choice: the good choice for you is to check the sock every week; If there is too much waste, it overflows and pollutes the swimming pools