They are constructed of 11 ga 2"x2". The supports that extend from the rail to the mounting point on the uni-body frame rails are 11 ga 1.25" square tubing. 11ga is about 1/8" thick. The angle that runs parallel to the main square tube is 1" x 1/8". They are 62" long to fit factory XJ rockers. I had them made for my XJ but them I cut my fenders and rockers so I can't use them.