Fi-Shock SC-77 Yellow Pin-lock Snap-on T-Post Insulators, 25-Per Bag One molded piece made from polyethylene with UV inhibitor that snap on and around all standard (1.25" and 1.33") stubbed T-posts Molded pin holds wire tightly Pull pin to release the wire The heavy duty flange holds insulator securely to T-Post 25 Insulators per bag