Unknown to collectors until now reference 2921 is seen for the fi rst time at auction. Considered to be one of the fi rst chronographs offered by Rolex as in 1937 the offi cial catalogue showed only 5 models. Slightly larger than most chronographs of that period at a diameter of 33 mm it was only produced in steel in very small numbers. Based on a Valjoux 13 movement this early example is the missing link between the similar reference 2916 and 2919 who all had similar designs namely its olive shaped pushers round case made by the casemakers “La Centrale”. The current example has remained in all original condition but still maintaining clean crisp numbers on the caseback and the original patinated dial. A must have for the rare Rolex chronograph collector