PLP dielectric support insert 00070251 (Millennium Part #521810) covers ADSS cable diameters from .430 in to .459 in. Each support assembly requires two insert halves when halves are ordered separately, so plan quantities in pairs per pole position. Sizing the insert to the measured cable OD is what keeps radial pressure uniform along the support, preventing the localized crush that shows up later as elevated loss on an OTDR trace. Because the assembly is fully dielectric, it supports ADSS in the supply space without introducing a conductive path, making it standard hardware for joint-use utility pole fiber builds.