Set yourself up for a great night's sleep with the Mainstays 9" Smart Box Spring. Offers the look and functionality of a traditional box spring but made from steel providing ultra-sturdy support for any innerspring, memory foam, or combination mattress, features a 100% polyester white jacquard covering that prevents shifting. This innovative box spring is designed to easily fold up for convenient storage and transport when not in use. The Mainstays 9" Smart Box Spring sets up in seconds with no tools required and is available in Twin, Twin XL, Full, Queen, King, and California King sizes to create the perfect sleeping platform in any bedroom. Mainstays 9" High Profile Steel Easy Assembly Smart Box Spring, Twin: Sets up easily in seconds Innovative design allows the box spring to easily fold up for storage and transport when not in use Provides ultra-sturdy support for any innerspring, memory foam, or combination mattress Features a 100% polyester jacquard cover Constructed with a durable powder-coated steel frame for a long life of reliable use Easy to assemble with no tools required Available in Twin, Twin XL, Full, Queen, King, and California King sizes Twin and Twin XL can support up to 600 lbs. total weight capacity Full, Queen, King, and California King can support up to 1200 lbs. total weight capacity Mattresses and bed frame sold separately Please see our assortment of mattresses Assembled Product Dimensions: Twin dimensions: 74" x 38" x 9"H - 26.3 lbs. Twin XL dimensions: 79" x 38" x 9"H - 26.8 lbs. Full dimensions: 74" x 53" x 9"H - 36.9 lbs. Queen dimensions: 79" x 59" x 9"H - 40.23 lbs. King dimensions: 79" x 75" x 9"H - 48.04 lbs. California King dimensions: 83" x 71" x 9"H - 46.74 lbs. Shipping Product Dimensions: Twin shipping dimensions: 41.3" x 11.2" x 10" - 30.5 lbs. Twin XL shipping dimensions: 42.1" x 10.8" x 10" - 31.1 lbs. Full shipping dimensions: 56.3" x 11.2" x 10" - 42.3 lbs. Queen shipping dimensions: 62.4" x 11.2" x 10" - 45.84 lbs. King shipping dimensions: 78.5" x 11.2" x 10" - 54.06 lbs. California King shipping dimensions: 74" x 11.2" x 10" - 53.13 lbs.