the wood post pigtail insulator is installed on the wood post by screw tip, please see the below pictures. if you want to keep the conductor away from the wood post over 20cm, it is better to use these wood post pigtail insulator, the length of the wood post pigtail insulator can be customized.

Normally, we have the 25cm wood post pigtail insulator and 40cm wood post pigtail insulator, also we have the double bracket pigtail insulator, the double bracket wood post pigtail insulator can keep the conductor away from each other at 80cm.