Convert your stock early magneto or "hex" type to the advantages of our MM3 style (see MM3 description). Kit includes the bearing bronze top ring, and the lower 'no leak' drive base crafted from stainless steel. Comes with instructions and all hardware needed. If you have the stock 'long shaft' type rotor, you will need to choose the "with rotor" option. If you already have a 3/8 hex drive magneto head instead of a stock XLCH and do not want the updated rare-earth rotor, choose "no rotor". Note: "with rotor" requires mag head dis-assembly. It may not pay to go this route if a lot of internal parts will also be needed. Contact us for more info in your particular case.