General description The Pcs Pool Winter Plug is designed to effectively block water return pipes, preventing rainwater from freezing and causing potential damage to your swimming pool's plumbing system. This 5-piece set is versatile, suitable for various applications including swimming pools, spas, and massage bathtubs. Technical specifications Material: Plastic Thread size: 1/2 inch Installation Easy to install by directly blocking the return pipe port. No additional fasteners required; installation takes just a few minutes. Usage Blocks water return pipes to prevent freezing. Can be used to seal skimmers, return lines, and detergent lines. Suitable for family garden swimming pools and spas.