I'm a little late to this thread, but my guess is the two black bolts are to be used IF you wanted bolt the ring to the kettle, as they fit in the two holes drilled into the roti ring. Of course, that means you'd need to drill through your kettle, which Weber won't sanction, but they seem to think it is a good idea. I can't see any other use for them (or the two holes in the ring) on the new style ring which fits quite tightly in the kettle bowl. I ended up drilling two holes in my roti and using those to bolts and those holding the motor mount to create a rest for a second grate. With a little foil over the U-shaped cutout and roti hole, the ring provides extra space which I find perfect for ABT's when I have ribs or a pork shoulder on the main level.