Sleep Number® Rolling Frames: Designed to Fit our Modular Base. Support your SLEEP NUMBER® mattress and modular base with a durable rolling frame. It features heavy 12-gauge steel construction, fits all industry-standard bed sizes and allows for a headboard attachment. Secure your bed in place with two lock wheels. Base sits 7" off the floor with 5" clearance at the side of the bed for storage under the bed. King frames have a center rail for additional support. Queen frame fits the Expanded Queen bed size. Easy assembly, no hardware necessary. Made in the USA.