The MRA is a revolutionary new device which aids starting by retarding the timing on fixed-position magnetos, helping to turn the infamous kick-backs and spit-backs into starts. When the cap-mounted lever is flipped, the points 'shift' 10 degrees, retarding your timing 20 degrees for starting. When the motor runs the lever is then locked in the advanced position by a rare-earth magnet. You'll love it! Fits clockwise turning Morris magnetos and other identically constructed magnetos like Joe Hunt, Fairbanks, etc. with cast housings.