The popular Field Guardian 8 in. Wood Post Screw-In Ring Insulators are used to hold polywire, hot coat and up to 3/8 in. polyrope 8 in. from wood posts. The ring insulator is often used for installing electric wire over a barbed wire fence to keep animals off the barbed wire. It is easy to set up, being quick and easy to attach to wooden posts with its built in screw. While not suited for high tensile applications nor a corner insulator, this electric fence insulator is made from high density polyethylene and is super durable because of that.