6 Volt regulator/rectifier for bikes with permanent magnet single phase ( Two Wire ) alternators. Great modern up grade for older bikes with separate regulator and rectifiers. Unit measures 3x2" and is good for charging systems up to 200 watts. NOTE: When used on Ducati singles with 3 wires (2-yellow + 1-red) the red wire is not used. Can be used on 6 volt bikes with negative or positive grounds.