The two chips listed in the guide CG007390 and CG020681 are identical front and back. However, the only difference in the two chips is the color sequence around the rim. Why the two numbers? Are the inserts reversed like the one I show in my example? At best, I think there in no variation on those two chips except the inserts reverse. Thanks Jim for your reply. Does anyone else see it the way I do or am I a lone wolf having this discussion?