As far as I know, there is only one version of the RS-1. It has been the top of the line consumer Grado (not counting the "professional PS-1) ever since John Grado took over the company from his uncle Joe. The only difference that I've seen among various RS-1s is the headband color. Yours seems to be a black leather band, while mine, which I believe is older, has a brown leather band. As far as sound goes, they should be identical. Hope this helps.
