I previously had the Innova 3555 timing light and I have to say I was less than impressed with that particular model. It seemed prone to inaccurate induction readings and fluctuations at random times; it got to the point where I just couldn't trust it and actually had to use an older timing light from the 1970's to confirm its readings and/or errors.After doing some research and checking reviews here on Amazon, I decided to give Innova's 5568 Pro model a shot. All I can say is "Wow, I'm impressed". This digital model is super easy to use. The directions are a bit lacking and confusing, but once you fire it up, it's very intuitive and easy to use. I was pleasantly surprised by how understandable the functions were once I started using it on the motor. Induction works 100% right out of the gate; no problems whatsoever. The digital timing advance/retard function worked really nicely also; you can push the arrows and watch the timing mark move forward or back 1 degree at a time. Very steady readings. I also appreciate that you can read the RPM's directly from the unit. This saves me from having to attach other diagnostic equipment. It's also nice to be able to turn off the flashing light when it's not needed.All in all, really impressed. Very nice timing light and seems to be very accurate and well designed/made. If you are considering between this model and the lower priced models, all I can say is the extra money gets you into a whole different ball park of quality. I wish I had gone with this model straightaway.