How many times have you gone to replace the muffler on a 2 cylinder Deere only to find that it already has at least 1 bolt broken off? With this tool, you can fix that! 
It comes with 2 bushings, one sized to guide the drill bit and one to make sure that the tap cuts straight. Use the existing good bolt holes to line up the jig. 
Fits Styled B tractors that have the muffler bracket cast into the top radiator tank. Will not work for 1939 model Bs.