Nemtek strain insulators are used at the beginning or at the end of an electric fence wire run. The strain insulator - Ultra is suitable for fence wire diameters up to 2.5 mm and a working load of 40 kgs. The strain insulator Ultra hardened is suitable for wire diameter of 3 mm and a working load of 140 kgs the strainer insulator - Ultra is available in black or white and the Ultra hardened in black only. Only virgin materials are used in their manufactures which are designed for a long life. They allow for larger creepage distance to reduce power loss.