1、Rubber and Stainless Steel Material: The pool winter expansion plug is made of premium rubber and stainless steel, ensuring maximum expansion and tight sealing for optimal performance and a secure fit. 2、Versatility: This plug serves as an effective pipe plug, blocking oil skimmers, return lines, and cleaning pipes, preventing water from entering the pipes during winter. 3、Multifunctional: The expansion plug can also be used for pressure testing pool pipelines or other leakage detection methods, as well as preventing water from flowing out of the pool during equipment maintenance. 4、Effective Protection: Protect your swimming pool from winter damage with the winterizing plug. This simple solution prevents severe damage to your pool caused by freezing temperatures. 5、Excellent Craftsmanship: With precise craftsmanship and an aesthetically pleasing design, this compact and portable pool winter expansion plug offers an exceptional user experience. Item Type: Pool Winterizing Plug Material: Rubber, stainless steel Purpose: Used as a pipe plug to stop skimmers, return lines and cleaner lines to prevent water from entering the pipes in winter. Expansion plugs also have other uses, such as pressure testing pool lines or other leakage detection methods, or stopping water from running out of the pool when performing equipment maintenance. 2 x Pool Winterizing Plug