When ordering a bumper, some options, like mounting holes , tow pin holes , and fog light holes are of NO CHARGE. However, options like BOLTLESS MOUNTING, FRENCHED IN license plate, CUSTOM OUTSIDE SHAPES like 1" or 2 " TAPERS or 4 INCH sides instead of STANDARD 3 INCH, LIGHT HOLE CUTOUTS on side of BOX BUMPERS and UNDERNEATH FLANGES will incur CHARGES.
For a BOLTLESS Option, the bumper comes with a bracket on each side. You mount the bracket unto to the truck, and the bumper mounts on the bracket using 4 bolts. 2 on top and 2 on the bottom. You won't see the usual bolts on the face of the bumper. Thus, the term " BOLTLESS".