Universal mounting for all RVs - front or rear. Fits most RVs regardless of the ground to frame clearance because it can be extended from 4 in. to 24 in.. Tooth gear designed scissor arms engage to ensure straight line vertical extension and retraction. Easy operating crank handle turns a double lead acme threaded drive screw for quick raising. Black rust inhibitive coating on the jack and shiny zinc-plated handle ensures long life. 7500 lb. lifting capacity. 2 per box.