Upgrade a wooden bed frame with the stable support of steel crossrails and a heavy-duty center support. Much stronger than wooden slats, the Adjustable Center Support System adjusts to fit full, full XL, queen, king and california king bed sizes. Three cross rails adjust from 52.5 to 77.5 inches and lock by thightening an attached clamp. Rails have pre-drilled holes for frame attachment. The center support adjusts from 53 to 78 inches for customized support, and three legs on the center support adjust in the height. Use the included allen wrench to adjust leg height from 6.5" to 15.5".