This. The blades are isolated.It's a device Leviton produced to test the function of TR receptacles. If you could push the two blades in but not the one, it's a TR.
wow... I can just see someone getting this and putting 7 60 watt incandescent bulbs on that 60watt keyless socket..
Neat! You could stack a bunch of them by screwing a long socket extender in the middle.