An AC pressure switch ensures proper operation and protects the system from damage. The switch monitors the pressure of the refrigerant in the system and, if the pressure falls below or rises above a certain level, the switch will shut off the system to prevent further damage. For an efficient and reliable HVAC system, the high pressure switch ac is a great choice for optimal syste... https://www.partshnc.com/010-buna-pressure-switch-laars-heating-systems-2400-106