Shubb Shubb Shubb is a company that specialises in producing capos for all kinds of stringed instruments. The company was formed in 1974 by banjoists Rick Shubb and Dave Coontz. Shubb capos remain a top-selling capo forty years after their invention. Shubb wanted to create a capo that would not make his instrument go out of tune, which has resulted in ongoing efforts to refine his invention. The Shubb Capo utilises an "over-centre" locking action, which is lever operated. The design includes a screw for adjusting the clamp's tightness, and has been described as "a turning point in modern capo design."
The Metal Airscrew Company Watts remained as chief designer from 1925-7 but moved to The Airscrew Company in 1932. Metal Propellers continued to advertise until at least December 1930. Metal Propellers Ltd were still sending apprentices to Saunders-Roe on the Isle of Wight for an initial training year in the mid 1950s The Metal Airscrew Company The Metal Airscrew Company was formed in 1919 by Dr Henry Charles Watts and Henry Leitner to produce hollow metal aircraft propellers with a method set out their joint patent. By 1928 the company name had changed to Metal Propellers Ltd. It remained active until at least 1930.