Instantly create additional storage space under your bed with these bed risers. Contains 4 large and 4 small bed risers, to customize to your needs. The bed leg or caster fits safely and securely into the recess cup built into the riser. How much room do you want under your bed? The small risers lift your bed up 3 inches, the large risers lift 5 inches, and for maximum under bed space, stack the risers together for 8 inches! The smaller bed risers nest securely over the locking ring on the large riser and will not slide. Made of high density polyethylene that won't harm floors or carpet. Each riser will hold a post or caster with widths up to 2.75 inches,