ZINUS 9 Inch Metal Smart Box Spring / Mattress Foundation / Strong Metal Frame / Easy Assembly, Twin XLWe like to think of a box spring as the backbone for your mattress. The best kind should be flat, level and built to keep your mattress in tiptop shape; and thats just what the Smart Box Spring does! With its easily assembled, dependable steel structure, you can rest assured that your mattress will be sitting pretty. An included poly jacquard cover blends with the rest of your bedroom, and with a variety of different thicknesses to choose from, you can pick the one you need to customize the height of the bed. All packed in a compact shipping box with everything included, even our 5-year worry free warranty! Now thats peace of mind you can sleep on.Steel Interior Frame With Knitted Polyester CoverTWIN XL DIMENSIONS The dimensions of this XL twin size box spring are 79 x 38 x 9 inches. The length is 5 inches longer than our Standard Twin size. Please measure your bedframe to ensure compatibility.THE LAST BOX SPRING YOULL EVER NEED Unlike a traditional box spring, the Smart box spring is made of solid steel that comes together in no time and is backed by our Zinus Peace of Mind 5 year warrantyDURABLY ENGINEERED Durable steel is used to construct the inside framework of this foundation; twin size supports a maximum weight capacity of 350 lbs, while Full, Queen & King sizes can support up to 700 lbsTHOUGHTFULLY PACKAGED All parts, tools and instructions are packed into one compact box that ships straight to your doorWorry-free 5 year limited warranty included; box spring only, a bed frame or platform bed is required to support this foundation and is sold separatelyProduct informationProduct Care InstructionsWipe with Damp ClothGlobal Trade Identification Number00841550078862MaterialAlloy Steel, FabricManufacturerZinusUPC841550078862Product Dimensions79 x 38 x 9 inchesItem Weight26.2 poundsCountry of OriginChinaItem model numberOLB-ABS-9TXLIs Discontinued By ManufacturerNoFabric TypeSteel Interior Frame With Knitted Polyester CoverWarranty DescriptionWorry-free 5 year limited warranty included.Batteries requiredNoIncluded ComponentsFoundation, Cover