Here is a side by side or the CD 145 STAR [010] with the Left insulator having the sharp threads and on the right is the standard rounded thread. Note the definite difference in the mandrels used. There is a pointed button in the top of the pinhole like the pennycuick and NOT an Elmer Ring. The insulator on the right has the Elmer Ring and the squared rounded threads. I am by no means stating these examples have a Pennycuick thread, but that it is significantly different.