Distributor-less plug-in ignition system for carbureted LS engines with 58X reluctor wheel. Several pre-programmed timing curves provided. Supplied software allows you to create cutom vacuum advance cureves, timing curves, program low and high rpm rev limiter and step retard. Plugs into stock sensors. MAP sensor provided. Compatible only with LS1/LS6 and LS2/LS7 ignition coils.