The PLP tie top polymer insulators are designed to match the head, neck and mounting pin requirements of ANSI C29.5, class 55-3, 55-4, 55-5, 55-6, and 55-7 as well as ANSI C29.6, class 56-1 pin-type insulator standards. C (2 -1/4 in nominal), F (2-7/8 in nominal) and J (3-1/2 in) neck sizes are available. By using ANSI head and neck dimensional standards, PLP metal or plastic factory formed ties will install easily and provide superior holding and electrical performance on PLP tie top polymer Insulators. Consult PLP for the suitability of other factory formed tie brands with these insulators. Covered or bare hand tie wire is also suitable for use with PLP tie top polymer insulators depending on conductor type.