The Proflo® Jr. is a totally enclosed electronic device, combining the latest technology in microprocessor and transistor components for detecting Slow-Flow and No-Flow of divider block lubrication systems. The Proflo® Jr. incorporates an oscillating crystal to accurately monitor the cycle time of the lubrication system to enable precision timed shutdown capability. The magnet assembly and electronics are designed to withstand extreme vibration for compressor applications. The Proflo® Jr. operates on a 3.3 Volt hermetically sealed high temp Lithium battery, with expected life of 10 years. If battery voltage drops below normal operating levels the Proflo® Jr. changes to alarm state and the compressor cannot be restarted. The LED flashes with each divider block cycle to enable the operator to easily set and monitor lubrication rates as recommended by the compressor manufacturer.