Extends electric fence wire 5 In. away from post to protect permanent or damaged fences. Insulator features exclusive unbreakable, snap-on, snap-off fastener attachment which accommodates standard size T-posts from 1-1/4 In. to 1-3/8 In. Made of high-density virgin polyethylene plastic with maximum UV (ultra violet) inhibitor for long life even in the toughest conditions.