The A22 Speed Switch precisely monitors rotating equipment and provides an output for “loss of speed”. The unit’s total package includes power supply, adjustable speed setting, 10 second delay, latching output relay, magnet, and explosion proof enclosure. The unit is highly accurate in spite of its low purchase and installation cost. Simple calibration allows the unit to monitor from 2 to 250 RPM (Optional 200 to 1000 RPM).