Expansion plugs also have other uses, such as pressure testing pool lines or other methods of detecting leaks, or stopping water flowing from the pool when equipment repairs are carried out. Use the gel caps to protect your pool from the harsh winter season. A simple solution that prevents your swimming pool from suffering serious damage. Specification: Condition: 100% brand new Item type: Extension plugs Material: Rubber Color: as shown in the picture Size: about 51 mm / 2 inches Weight: approx 190g / 6.7oz Application: Used as pipe plugs, to plug skimmers, returns and cleaner lines to prevent water from entering pipes during winter. Expansion plugs also have other uses, such as pressure testing pool lines or other methods of detecting leaks, or shutting off water flowing from the pool when equipment repairs are made. List of packages: 2 x extension plugs