Well, if you want cheap, this certainly is cheap. It can only measure FPS, good for paintball.
They neglected to include Xcortech on the comparison chart.
A chrono is an investment. If you are tuning your gun and need to know where your performance is at, get a Xcortech.
It measures, RPM, RPS, MPS, FPS, calculates Joules as well by allowing you to input the bb weight and size.
http://airsoftdepot.ca/catalog/index...hnl1hka3mfpq11