1.competitive price 2.manufacturer 3.good quality 4.safe usage 5.large production capacity to ensure delivery on time Shackle /Spool InsulatorStandard: 53-1, 53-2 53-3, 53-4, 53-5, R-8, R-6, R-2, R-1, 1617, 1617-1, 1617-2, 1618-1, 1618-2, 1618-3, ED-1, ED-2, ED-3, ED-4, ED-2B, ED-2C, S. 03, S. 05, S. 1, S. 2 Spool porcelain insulator