SWITCH, IGNITION, TWO POSITION, ASSEMBLED WITH LOCK & KEYS, REPLACEMENT
Part Number 391-30608/ER/A
Used on many late 1960's and early 1970's bikes:
AJS, Matchless 750cc, BSA B25, C25, B40, B44, A65, A75
Norton Atlas, Commando before 1970
Triumph T100, TR25, TR5, TR6, T120, T140 etc.