Function: These expansion plugs are designed to winterize your swimming pool, protecting it from harsh winter conditions and potential damage. The tapered plugs, made of rubber, can be used to seal holes, pipes, drains, sinks, tanks, and other openings in your pool, kitchen, bathroom, or yard. Ideal for use as pipe plugs to seal skimmers, returns, and cleaner lines to prevent water from entering the plumbing during winter months. These expansion plugs can also be used for pressure testing pool lines, leak detection, or stopping water flow during equipment repairs. . Material: Rubber + Stainless Steel Color: Black Package Contents: 6 x Pool Plug (2 x 25mm, 2 x 38mm, 2 x 51mm) Note: Only the items listed above are included. Other products are not included. Light reflection and differences in display screens may cause slight variations in color between the image and the actual item. Measurement error allowance is +/- 1-3 cm.