I have no idea what CEW was thinking with this concept insulator. At first glance the spiral groove seems to be for easy insulator replacement but they didn't bother to take out the original wire groove. Some speculate that the original wire groove was left in place as a back up if a pin when missing. The insulator could then be turned upside down or horizontal and screwed in to a tree, pole or crossarm and still be usable...

J/K :)