Give your sleep the support it needs with this Sierra Sleep firm, tight-top mattress. tight-top mattress innerspring system polyester/other twin: 74x37x13H full: 74x52x13H queen: 79x59x13H king: 79x75x213H cal. king: 83x71x13H made in America Includes mattress only. Mattress plus box spring option also available. Signature Design by Ashley is a registered trademark of Ashley Furniture Industries, Inc.