Features 1. Material: The winter expansion plug is made of high-quality rubber and stainless steel bolts, ensuring reliability, stability, rust resistance, durability, and resistance to breakage. 2. Function: Designed to block swimming pool pipelines after drainage, preventing water from entering and causing ice damage. 3. Easy to Use: Simply screw the plug into return and drain ports for quick and effortless installation. 4. Usage: Acts as a pipe plug to seal skimmers, return pipes, and cleaning pipes during winter to prevent water intrusion. 5. Multifunctional: Suitable for pressure testing pool pipelines, leak detection, or preventing water from draining out. Specifications Material: Rubber Plug Sizes: 25 mm, 32 mm, 38 mm, 45 mm, 51 mm, 63 mm Color: Black Dimensions: 4 x 3 x 3 cm, 4 x 4 x 3 cm, 5 x 4 x 3 cm, 6 x 4 x 4 cm, 6 x 5 x 4 cm, 7 x 6 x 5 cm Weight: 31 g, 48 g, 65 g, 83 g, 100 g, 120 g Package Includes: 1 x Expansion Plug