浪琴，罕有及獨特，不銹鋼單按鈕針時碼錶，配黑色錶盤及中央分鐘計時子盤，”Stopsecond”，型號5681

According to the Archives of Longines, the present watch, a reference 5681, was manufactured in 1950 and invoiced to the company's agent at the time Nederlandsche Horlogehandel or N.H. in Amsterdam, Holland, on 8 September 1950. The movement of the watch is registered as a 12.68 Z stop.

The "stop second" fly-back chronograph watch was commonly destined for military purpose and is increasingly difficult to find. This particular watch boasts a fine silvered tachymetre scale, nicely contrasting against the black gloss dial background.

For another example of a Stopsecond watch see Longines Watches by John Goldberger, pp. 142-143.