The Birmingham, England based firm of OK began volume production in 1911, concentrating on two-strokes, notably the Junior. The firm changed its name to OK-Supreme in 1927, the year before Frank Longman won OK-Supreme's only TT win. The most famous bike was the early 1930s single, coming in 250 and 350cc forms, known as the Lighthouse after the glass inspection plate they featured on their camshaft tower. The Flying Cloud was a cheap and reliable model that was very popular in the late 1930s. After the Second World War, the firm only built a few grass track bikes.