The model AFS-303-112 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. AFS-303-112 can be used to sense positive, negative, or differential air pressure. The AFS-303-112 is equipped with convenient barbed sample line connectors that accept flexible tubing.

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.