... products for many years We specialize in producing this Line Post Insulator widely used on distribution line ,net work, transmission line and ... other power line . The insulator ... 57-1, 57-2, 57-3, 57-4, 57-5, 57-11, 57-12, 57-13, 57-14, 57- ... to ANSI C29.7 , IEC383 and BS137. 57-5 line post insulator