CE Compass New Digital Laser Photo Tachometer Non Contact RPM Tach
This is a Digital Photo Tachometer. It measures the rotational speed with a visible red light beam from a powerful LED. Just attach a reflective sticker to the rotating part and point the beam on the mark from a safe distance.  It is a great tool to measure the RPM of motors, engines and machine parts. In wood and metal working it can be used to accurately measure the speed of a lathe or milling machine.