I'm with Will too. It has several useful functions, but most important to me is to confirm that the n20 systems are working. If NOT, it may because of a problem like a sticky Noid malfuctioning, wiring issue, etc. OR, it could be that I had a brain fart & forgot to Activate the n20 system, or open the bottle valve. It does "clean up" the n20 systems, and you will see this from the 1st motor bang to the 2nd to the 3rd...at least in my case. And YES, it is useful to know if there is a problem, and the systems are not working, because I'd rather just abort the pass, instead of launching like a pig with no N20! To each his own...