This strong support system is designed to replace wooden slats. Three adjustable length steel cross rails and a heavy-duty center support rail create a stable foundation for full, full XL, queen, king and California king size beds. Setup is simple. Slide the rails to the desired width and hand tighten attached clamps. Cross rails have pre-drilled holes for the option of securing rails to the bed frame (screws not included). Adjust the center rail and legs for a customized fit to your frame. Use the included allen wrench to adjust leg height from 6.5 to 11 inches.