Hi James
I have the same bracelet fitted to my Modena. It has a great clasp that easily adjusts to size without fiddling with springbars. Its only the ends that are specific to the model and so we can only assume that it was available as an option in one or more regions. My Modena came from Germany. This may have been at the time when the GF's were being phased out and there is no doubt that they would have been a cheaper alternative.
regards
Paul
www.heuerworld.com