Valves, inlet, Norton twins 1949-1960 (ea), also ES2 inlet with AMC motor 1964-66. length: 3.9 in;Stem diameter: 5/16in; Head diam: 1-5/16 in 1.3125 in 33.3mm; Wt 60g.Original part numberD12/142, T2010 - valve inlet