The one I have is 4-5 years old, I know they have them now with alot more functions. Mine measured o-60mph times, and 1/4mi time and speed...although its instant speed and not trap avg speed. Also measured g-forces side to side and front to back but never used it for that. For 1/4mi times, I used it at the track a few times to see how accurate it was and it was always within 0.1 of the track time and usually the mph was 2-3pmg higher because of the instant speed. I was amazed, so it is very accurate I'd say. Really all it is is a accellerometer, which is a fairly simple device that measures very accurrately...just make sure it is mounted very level or it will skew the results, I usually lodge it up at the base of the winshield so it can't move around or bounce to get the best readings.