Product Description: Sealy® Flat Foundation 9" matches the traditional box spring while offering more support and comfort. This durable foundation is engineered to provide a solid base for your mattress and upholstery to complement any mattress. Designed to absorb motion, this Stablesupport™ foundation cradles your body and prevents mattress sagging so you wake up rested. Suitable for all types of mattress, from foam to innerspring. Fits most standard bed frames.