This is the DT2234C+ Digital Laser RPM Tachometer Non-Contact Measurement Tool! The housing has been carefully shaped to fit comfortably in either hand. It is a great tool to measure in wood and metal working or many other kind rotary devices. It can be used to accurately measure the speed of a lathe. The reflective strips which stick on the rotating equipment are mainly used for reflecting the laser signal by the tachometer.
WARNING: DO NOT STARE IN THE LIGHT