A 20th Century American lever with black 24 hour dial by Hamilton in a silver open face case. High quality 4992B model damascened nickelled split three quarter plate keyless movement, going barrel, centre seconds transfer work above. Plain cock with polished steel micrometer regulator. Compensation balance with overcoil hairspring. Club foot lever escapement, escape and lever pivots with endstones. Black dial with centre seconds, white Arabic numerals, the outer chapter for the minutes and the inner for twenty four hours, white hands. Silver 800 standard Keystone open face case with screw bezel and back.