Here are two unusual power insulators -- will add actual postage:

First is a CD 300 LOCKE [075] No. 17 // F.M. Locke Victor N.Y. // 5 patent dates (1 on ear) -- aqua with decent amber swirling - inner most skirt chipping and some flaking inside the skirt at the mold line (typical) -- $85

Second is an unlisted CD 300 variant -- it has a small top like a CD 297! it also has a standard 1" pinhole -- F.M. LOCKE VICTOR N.Y. // 5 patent dates - light aqua -- only issue is an internal fracture in the inner skirt on the backside going un about 3" - no glass missing -- very unusual piece! -- $125 (SOLD)