The slide out supports save wear and tear on slide outs by reducing sag, can effectively solve the sagging and bending in the slide-out rails, and help prevent costly slide out frame repairs.Hand operated lifting jacks. Heavy-duty steel and zinc powder-coating finish provide maximum strength and longevity for these rust-resisting RV slide out stabilizers. A folding handle allows jacks in small compartments. 2 per box, easy to operate, no assembly required. From the lowest setting, use the folding handle to raise the bracket slowly to meet the RV slide out supports bars. It is suggested to use concrete blocks or wooden leveling blocks for campers to stabilize the RV slide out jacks on an even surface.