I've had this non-contact laser tachometer for a few years and it has been working well for me. I use it for things like adjusting or verifying speeds for motors, squirrel cage blowers, fan blades and pulley setups. You place a small strip of reflective adhesive tape on the surface you want to read the RPM's for and aim the tach's laser dot at the tape from up to 6-feet away. The tach then reads the reflected laser light. The tachometer came with a storage case and a small roll of white reflective tape, but you can buy a larger 50-foot roll of 1/2" wide 3M tape here on Amazon that should be enough to last for several years of use. For such an inexpensive digital tachometer, I find that it is quite accurate. The display is not backlit, but has large digits and displays up to 99,999 RPM's with Min/Max memory for the last reading. I've seen this tachometer with the same specifications being sold under several different names now, but don't know if there is any difference in build quality.