Are you talking about the adhesive anti-slip material attached to the retractable step? You mentioned high winds, so I assume it couldn't be the inside rubber stair tread coverings, correct. If you do mean the non-slip covering on the retractable stair step, those I have seen on amazon . Amazon.com: 3M Safety-Walk 7768 6 by 24-Inch NA Reflective Tread: Home Improvement
I'd shop that item for price. Maybe CW carries it, but they gouge pretty good. If this is what your asking about, and find it cheaper, let us know.