The Dare Electric-Powered Fence Insulator Yellow WESTERN-RP-25 is designed for a long-lasting, durable performance. Featuring a wide range of compatibility, this insulator fits most 1/4" to 9/16" diameter posts and 5/8" fiberglass T posts, while extending wire 1" from post for optimal efficiency. Its adjustable design allows for installation without the need for additional tools and guarantees a secure fit while the current is still "on". High-density polyethylene with UV inhibitors ensures this insulator stands up to the toughest outdoor conditions.