Fits all steel T-posts, 1.01, 1.25 and 1.33 lb/ft. and can be nailed on top of wood post. For all Wire, Polywire, Polyrope, and tape up to 1 1/2 inch. Protects horses and other valuable livestock from sharp, jagged T post tops. Large heavy-duty cap/insulator can be installed with wire holders facing front, back, right or left.