Mine Rescue Alarm (MRA) is an MSHA Approved Personal Distress Alarm specifically engineered for Mining and Tunneling Workers. This small, lightweight and very loud alarm can be worn by miners, maintenance personnel, inspectors, or anyone who enters a mine for an extended period of time, with the possibility of becoming trapped and needing to summon help. Features of this product are: approved for use in gassy underground mines, push-button emergency “Alarm”, lack-of-motion detection, water-proof, corrosion resistant, and optional temperature sensing.