Are you having trouble keeping your wire securely attached to your posts? These American FarmWorks Pinlock Wood and T-Post Insulators for 1.25 and 1.33 in. T-Posts tightly fasten electrified wire to wood, metal, and T-posts (1.25/1.33 in.) without losing energy through the post. Carefully molded pins hold the wire securely inside the electric fence insulators. If you need to release the wire for repair or re-spooling, simply release the pin! Use these versatile black pin-lock wood and T-post insulators with traditional steel and aluminum wire, polywire, and polyrope. These electric fence post insulators are made with UV-stabilized polyethylene to resist damage from sun exposure.