used been kicking about amal 389 689 Monobloc threaded ring for air filter or air filter hose to push over brass 14.5 mm length internal dia. on thread = approx 43mm external dia approx 47.5 mm with a thin lip of 51 mm but may work with other makes enfield panther norton ariel ajs matchless triumph Carb shown is NOT included , to fit triumph triton tribsa BSA norton sunbeam PANTHER ARIEL AJS MATCHLESS velo etc etc ,
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