The model AFS-304-112 is a general purpose proving switch with gold contacts designed for HVAC, Energy Management and DDC (Direct Digital Control) applications. Gold-contact switches are used in computer environments, direct digital control, or wherever low ampere currents are wired. It can be used to sense positive, negative, or differential air pressure.

The plated housing contains a diaphragm, a calibration spring and a snap-acting SPDT switch with gold contacts. The sample connectors located on each side of the diaphragm accept flexible tubing.