The Side-Pin Heavy Duty Square Jack From Buyers Products Features A Spring-Return Drop Leg That Allows Easier Expanding And Retracting. The Spring Return Is Activated By Pulling A Sturdy Side-Mounted Pin To Drop The Leg. Ideal For Rvs, Construction Trailers And Triaxial Trailers, Each Jack Has A 10,000 Lb (Dynamic) And 12,000 Lb (Static) Capacity. The 4 In. Square Tube Features A Weather-Resistant Black Powder-Coated Finish, And Includes A Footpad.