Low voltage, single pole double throw, molded base with plated metal contacts and screw connectors

Plug Key Switches as they are commonly refered as.

Some of them are as below, tapping Key - Single and Double.

It is a basic electric switch with two terminals for circuit to use in physics lab experiment.

Strong base with rust resistance terminals and one plug key for making or breaking the circuit.

Plug key completes the circuit for current to flow and when it is removed circuit breaks.