RPM reading 1 spark revolution. Single coax cable to carry signal without EMF interference. 1 antenna cable winds around your spark plug wire to give you the RPM reading. Design Technology Inc. Fits/For most gas outboard marine engines, most 1 or 2 cylinder, 2 and 4 stroke small engines like Briggs & Stratton, Kohler, Toro, Honda and Lawnboy with 1 spark per revolution.
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