The thread: 14x1,25 mm. Adapter is made from steel in "golden" zinc coat. This device is very useful In adjusting ignitions of a variety of engines (Triumph, Norton, Harley-Davidson, Indian, Simson, NSU, DKW, BMW, AJS, BSA, Zundapp, MZ, Honda, Suzuki, Yamaha, Kawasaki etc.).
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