Centura... That's what those are called..

The Orange Co courthouse has these all over the place, I thought they were just some funky decora device I'd never seen before that had a ridge between the 2 outlet openings.. (Well, I guess they ARE a funky decora device when it comes down to it LOL)

I've got some old Bryant toggle switches that I pulled from a house dating back to the era of the edison base outlet (1927) but all the outlets in this house were regular NEMA 1-15 or 2-15 (the T slots) made by Arrow Hart.

When did use of the edison base outlets seem to end? I've worked on houses and buildings dating around turn of the century and have yet to come across one here.

Randy