The tach is but you need an ignition with the extra wire for the tach. My gas engines are older and don't have the added lead. I need a new ignition for my RCS and plan on buying the ignition used for the DLE 30 so I will order a tach when I order the ignition. Hobby King has some good prices on both. The tach is very small too and the one I was fooling with was hard mounted in the planes fuse.