Those look somewhat similar to Roger Brown's Rock Sliderz design - the outer tube bears the weight and the inner tube is located under the body pinchweld and will distribute the weight into the body when the Rock Slider flexes under load.

http://www.4crawler.com/4x4/ForSale/RockSliderZ.shtml


95 Montero SR
3.8 MIVEC, Advance headers, 2 1/2" exhaust, Magnaflow muffler, OME shocks & rear springs, 2" body lift, 3" tank lift, 4.90s, TRE front locker, factory rear locker, Roger Brown Rock Sliderz, 315/75r16 (35") tires, Sport big brakes