AJS/Matchless Piston 350cc STD. for Alloy Cylinder Headgudgeon pin = 22 mm 7/8" 7,5:1 D: 69mmtotal hight 85 mmincluding gudgeon Pin, piston rings and circlipsPiston Clearance 0.12mm or 45thou347 cc OHV 16M 1948-55347 cc OHV 16MS 1956-58JP Piston Made in AustraliaMeasurement see pict.