While the Speedmaster models with calibre 321 are getting more scarce, many of you are after the Speedmaster Professional 145.022. This is the reference that was introduced in 1968 and did not only have a printed logo on the dial and a new seconds hand, it also came with a new movement. The calibre 861 movement was also Lemania based, but instead of a column-wheel mechanism, it uses a cam / shuttle system for the chronograph operation. This new movement (different balance wheel, higher frequency, new construction etc.) was the basis for the movement that we still find in today’s Omega Speedmaster Professional ‘Moonwatch’ models, the calibre 1861.