SAFETY AND QUALITY: The screw in agricultural fence screw insulators are completely environmentally friendly, completely harmless to people, pets and wildlife. These threaded ring insulators have the advantages of sun, rain, weather protection and long service life. * DESIGN FEATURES: The ring insulators fence groove design can securely fix the wire, reduce wear and extend the life of the wire. The bit can be faster and easier to install on the insulator on the woodpile, saving time and effort. * SCREW DIAMETER: Total length: approx. 9cm / 3.54 inch. Metal Part Length: Approx. 42mm / 1.7 inch. These ring fence insulators easily adapt to the wooden fence, no special tools or know-how. * SHORT CIRCUIT PROTECTION: The ring fence insulator prevents short circuits between wires and fence posts and maintains the space between wires and fence. Suitable for high tensile steel wire, aluminum, stranded wire, etc. * 20 PIECES: Threaded ring insulator set contains 20 Spacer ring insulator, made of high quality material, sturdy in construction and study, as essential accessories for electric fences, convenient to replace the broken one.