It is a pretty fabulous gadget. Extends the step length about 1" which is nice, at least on our rig. And when creeping along in the sea of cars, vendors, and disabled beggars at the north-bound Tijuana border crossing into the good ole U. S. of A. (and trying your best not to run over any of the character-pedestrians), it acts as a perfect K-rail feeler. Mine has a teeny scrape in it from such a get-together; that woke me up

But the device took a lickin and kept performing its neat neon trick.
Oh yeah, you drill four or five small holes thru the vertical face strip of the step for some (aparently) high test bolts that are integral to the step extender. It adds a nice non-skid to the step as well. Sure is nice when coming home in the dark when I forgot to turn the porch light on.