This is a Locke M-2617C that I shook down from a pole on an abandoned power line in rural South Carolina. The power line, which I will post shortly in Line Construction Details, holds mainly these and M-2250B's, but I have also seen one large hi-top unipart. This insulator is missing a large chunk of its top skirt, but it was already like that before I took it down. It seems the locals have taken to shooting at the insulators, as many on this line (and a nearby feeder, still in service) are broken. My brother also managed to get one of the M-2250B's in near-mint condition.