THIS IS A NEW UNIT AND IS FOR 12v ELECTRICS TO FIT KICK OR ELECTRIC START PIT BIKES. THIS COULDNT NOT BE ANY EASIER TO FIT, SIMPLY PLUG & PLAY! INCREASES LIMITS THROUGH REV RANGE. PLEASE NOTE THIS ONLY TO BE USED ON ENGINES THAT HAVE BEEN RUN IN. I WILL NOT BE HELD RESPONSIBLE FOR ANY DAMAGE DONE USING THIS PRODUCT. IT WILL NOT FIT MONKEY BIKES WITH 4 WIRE CDI UNITS. PLEASE NOTE YOU WILL NOT FEEL THE FULL BENEFIT IF YOU ARE STILL USING A STOCK CARB AND EXHAUST AS THEY WILL RESTRICT YOUR BIKE. FITS ALL PIT BIKES WITH LAYDOWN ENGINE BUT NOT UPRIGHT SUCH AS 200 OR 250cc.