I have found it hard finding any info on any website regarding the Jackson JS20RR. Not even on the Jackson website regarding this particular model. I am pretty sure it is a discontinued range of guitar.
I can tell you that it has 22 frets as opposed to my other Jackson guitar having 24 frets. It has two Jackson humbucker pick ups, (not sure if they are EMG endorsed ), shark fin inlays, triple locking system on the head and Floyd rose system on the base of the guitar. It has one control knob for volume and a switch to alternate pickups or to use both simultaneously. Like my other Jackson guitar, I found this one secondhand online for $300. It was set at standard E tuning, though since I have had it, I have had it restrung and have it tuned to dropped C tuning. Again, being a Jackson I cannot fault this guitar. It just kicks ass !!!