What switch is this?

[NCHusky1]

Good evening, I replaced three old single pole switches with Kasa smart dimmers with no problem. But I encountered problems with the switch below. I cannot find my multimeter to test it. Anyone recognizes what type of switch is this? What the two holes are for ? Thanks!

 

[NCHusky1]

Are these two holes so called backstabbing holes? The switch was made by UND Lab.

 

[westward10]

Yes they are. They should be the same terminal as the adjacent screw connection, @Megawatt will confirm.

 

[Megawatt]

Good evening, I replaced three old single pole switches with Kasa smart dimmers with no problem. But I encountered problems with the switch below. I cannot find my multimeter to test it. Anyone recognizes what type of switch is this? What the two holes are for ? Thanks!

View attachment 102820

The 2 holes are for back stabs or just another place to terminate your wiring. My question is why 3 black wires connected to the one screw which is not allowed. The switch is just a regular switch that will accommodate 2 wires per screw white 1 wire in the back and 1 for the screw