The YTD-309-120 with 100mA 12V SPST Solder Lug Round plunger Plugin Microswitches ROHS is an electronic component manufactured by DGBZ. It is a type of switch which consists of a pin or plunger on one end, a contact point on the other, and an actuating spring in between. When the plunger is pressed, the contact point closes, allowing electricity to flow and when the plunger is released, the contact point is opened, stopping the flow of electricity. This switch is RoHS compliant, with a maximum current of 100mA and a maximum voltage of 12V. It also features a solder lug for easy installation and an optional round plug in for a clean interface.