The first evolution of the Rolex Explorer II came in 1985, with the reference 16550, marking the most significant update of this model. Differences were both technical and design-related. The movement, for instance rolex replica watches usa, was now the calibre 3085, which allowed the 24h hand to be set independently. This meant that the Explorer II became a dual time zone watch - while the GMT-Master became a triple time zone watch.