Bulldog's 8,000 lbs. support capacity square jacks serve the agricultural, industrial, construction, horse-livestock trailer, and utility-Tractorgo trailer markets. The compact design of these jacks makes them ideal for tight-fitting applications. This is a perfect transition from Bulldog's round jack product line. Use the painted outer tube as the final finish or primer. Zinc-plated inner tube and drop leg. 4.7" Outer/inner tube overlap - results in optimal side load performance. 5/8" screw stem - provides insurance against screw stem twisting off. Patented screw nut stop - prevents screw and/or nut damage when jack is fully extended,