Peter,
It's exactly 36" long and is made from nominal 1X12 lumber (actually
3/4" X 11 1/4"). Pics and a brief description are at:
http://www.oldengine.org/members/jdunmyer/airstream/
I deploy the A/S step when at home, but seldom to never when on the
road, using the step box instead.
<<Jim>>