Snap action switches are highly sensitive switches that respond to very small movements and can rapidly change from one contact position to the other. The HM series hermetically sealed basic switches are designed with a gas-tight seal to transmit force and motion to the switch mechanism through a metal diaphragm. These highly sensitive switches are very often used in adverse gas or vapor environments, oil drilling installations, marine environments, submarines and stationary undersea equipment, refrigeration units, aircraft and spacecraft, earth moving machinery, desert vehicles, cement mills.

2HM19-1 Snap Action Switch from Honeywell comes with an operating force of 1.95 N and an operating temperature ranging between -65 to 125 °C. The Roller Lever Switch contain contacts in a sealed chamber.