... made of fiberglass or ECR-fiberglass (FRP/GRP) epoxy resin 2.high mechanical strength FRP Threaded Rod is made of fiberglass ... or ECR-fiberglass (FRP/GRP) and epoxy resin, With high mechanical strength and ... composite insulator, pocelain insulator, composite hollow insulator, Pillar insulator, cross arm insulator, electric railway insulators, HV switch, drop switch and other ...