May 2014 Trailer Life magazine. I looked at this and wondered the same thing. Things that come to my engineering mind are, wonder how this would work on the average gravel ground. Bet it would be more effective on concrete. Also wonder about the protruding lumber on the outside the sides of the RV (mine would be covered by the slides in the rear). I'd worried about someone tripping on the lumber especially after dark (folks staggering home after happy hour!) :) Think that treated lumber, as it is harder and therefore more robust. Wonder about using 4X4 instead of 2x4 (would be heavier to deal with and carry)? Thought that you'd have to countersink the eyebolt holes on the outside so the nuts and washers would be seat flat in the lumber. Just my thoughts and analyzing...no actual experience. Be interesting to see what others experience. rockin'