Insulate your round fenceposts with Gallagher Screw-on White Rod Insulators. They fit round posts from 1/4" to 5/8" (6-16mm) in diameter. They're easy to install and adjust, making them perfect for multi-wire portable fencing. The heavy-duty threads won't strip, making these a long lasting option. | Gallagher Screw-On Rod Insulator in White | Size 25 Pack