The name 'Unit' was given by Thornton-Pickard to a self-capping, quick-wind, focal-plane shutter introduced in 1909. From 1910 the shutter was made separately from the reflex camera to which it was originally fitted and the Unit prefix was given to a series of the their own cameras fitted with this shutter. 'The working parts of the shutter, apart from the blind, are of metal, and mounted on a single metal plate, the whole being simply mounted in the outer case of wood'.