SimPoolTech Winterizing Skimmer Plug for In-Ground Pool (Pentair Admiral In-Ground Skimmer) EASILY WINTERIZE IN-GROUND POOLS: The Skimmer Plug closes off the skimmer and protects it and the piping from freezing. Fits like a "cork in a bottle" NO MORE WORRY OR HIGH COSTS: A simple and proven cost effective method to winterize your skimmer without draining any water. No tools required, simply push in place! PLUG & PROTECT ALL WINTER LONG: Made from RovaSeal , a high density water blocking foam that is both UV & Chemical resistant, the Skimmer Plug is a high quality and durable winterizing tool FITS SKIMMER MODELS: Pentair Admiral Skimmers - Measures 7 3/8"W X 5 1/2"H. Refer to description for how to properly measure your skimmer ONE YEAR USA MANUFACTURER WARRANTY: Buy in confidence, with a complete peace of mind. Join the thousands of pool owners using Skimmer Plugs this winter!