Made of virgin, high impact polyethylene. Designed to eliminate moisture collection. Large wire channel accommodates all wire sizes including the heaviest barbed wire, the lightest gauge smooth wire and Red Snap'r electric fence wire. Easy installation with 45° front loading feature. Provides long arcing distance protection from wire to post. Self-centering post cavity with spin-on nut will accommodate posts ranging from 1/4 in to 9/16 in diameter.