Narrow chain of high elegance for high level performances. The exclusive << BC >> feature of the riveted bushes allow for an extraordinary resistance to shocks and working stresses.
From 78 Regina Catalog:
Narrow chain for high level racing. In addition to the exceptional resistance provided by the << BC >> riveting of the bushes and the high quality materials, the 50 Record chain features an extreme lightness obtained through the special design of the plates and a lightening hole in all outer plates.