Model 25-7D Master clock with special dial, figures and hands. No.21285,International Time Recording Company Ltd., London, 1950-1959. It was electrically self-winding. The Master Clock was part of a Minutue Impulse Time System, which involved other time recorders which took their time from this one. A Master Clock, Model 25-7 by ITR Ltd, 1950-1959 1950-1959
