This is the Regular Gizzmo, it is designed to absorb the expansion of winter freeze-up in swimming pool skimmers. The Regular Gizzmo is 9 inches long and installs in short skimmers found in both above and in-ground simming pools. The Regular Gizzmo has 1 1/2 inch threads and features a generous bar style grip for easy handling. For a professional fit, the Gizzmo can be used with Teflon tape. Teflon tape is a very thin white tape used to wrap the threaded ends of pipes to improve the water tightness of a joint. The Gizzmo is designed for single season use, please remember to recycle this product.