●STRONG AND STURDY ELECTRIC FENCE INSULATORS. Made of high quality plastic & metal materials, anti-rust, not easy to break and will last a long time. ●EASY TO INSTALL. Pls drill pilot holes for each post first, and then screw insulator rings right in, ad the wire to, and they holds wires well. ●VERSATILE FENCE POST INSULATORS. Widely used on any type of fence post, like wooded fence and horse fencing, protects wire from damage. ●SCREW-IN DESIGN. Great wood post insulator, better than the nail-in Insulator, more durable, and they wont move once screwed in the post! ●PACKAGE INCLUDES: 20 PCS eletric fence srew-in insulators. Size: Approx. 9 x 3.5cm/3.54 x 1.38 inches. Perfect size to walk the wire through.