Developed, constructed and used successfully for many years on most 2T bikes by a two stroke junkie. This device eliminates the need of a battery on magneto type ignitions. Less weight, less mass, environmental friendly, no danger of acid spills/ corrosion, maintenance free. It will straight fit any Tzr250, Tdr250, Rgv250, Nsr250, Rd350, Rd500 bikes and also most single cylinder bikes. Though, it will not work on racing machines that are running a total loss ignition system. I've been using them for over 5 years now with great success. Can't even remember when I last bought a battery... Battery eliminators are now available through ebay. Have fun, keep the two strokes alive.