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" to 24". 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.