【Material】The winter plug is made of high-quality rubber, which has the largest expansion and good sealing performance and can be used for a long time. 【Excellent performance】After the pool water is drained, the rubber plug is used to seal the pipe to prevent water from entering the pipe and causing the water to gel. 【Multi-purpose】Used as a rubber plug to block oil skimmer, return water and cleaning lines to prevent oil from entering in winter. It is also possible to test the pressure of the pool pipe or stop the flow of water into the pool during equipment maintenance. 【Product packaging】 You will receive 2 swimming pool antifreeze caps. Size: Approx. 38mm. Specification: Item Type: Expansion Plug Material: Rubber Color: As shown in the picture Weight: Approx. 145g Application: As pipe plugs, used to seal pipes skimmers, returns and line cleaners to prevent water from entering the pipes in winter. Expansion plugs can also be used for other purposes such as pressure testing pool