Just think of the things you can easily accomplish with our GMR pickup. This little device simply attaches, with no splicing or cutting, to a current carrying wire and turns that information into a 12 Volt RPM signal. This signal can be used to activate a shift light, RPM activation switch or a tachometer. One example is to connect the GMR, which stands for giant Electro-Magnetic, to a diesel injector current wire. This will produce a signal that can be used to trigger a tachometer or shift light. Another example is on late-model engine equipped with a coil-on-plug ignition system. One of the coil's primary current wires is simply routed into the pickup clip and GMR converts this pulsing into a 12 Volt signal for a shift light.