Rocker Panel Kit

About 3 years ago I received a rocker panel chrome kit for a ’94-’03 S-10/S-15 extended cab short bed with fender flares and rubber bumpers. The box states it is for trucks w/o flares but the salesman and also the website says it is used w/ flares, has anyone ran into this where they had to modify the trim to fit the truck with flares? Question two, what are “rubber bumpers”? The reason I ask is I am planning on selling these and would like to know incase someone was interested in it and wanted to know what that meant.