This timing light includes a full range of options designed to meet the demands of DIYers with many of the features that professional installers demand. It also provides the additional ability to check the operation of your vehicle's mechanical or vacuum advance timing controls which ensure that ignition occurs at the proper time. Can be used used for 12-volt negative ground vehicles equipped with conventional breaker point and electronic ignition systems, also distributorless ignition systems. Advance dial enables user to check base timing, mechanical advance or retard, electronic advance or retard. Rotating barrel for better aim at timing mark, metal inductive pickup, and protective hand guard.