Suggested Retail: $80.57. NEW Amazon Basics Smart Box Spring Bed Base, 5-Inch Mattress Foundation - Twin Size. The look and functionality of a traditional box spring, but made from steel to support any spring, memory foam, or hybrid mattress. Durable steel frame and horizontal slats provide sturdy, reliable support for any same-size mattress. 2-piece fabric top and bottom covers the frame and zips together for full coverage; cover is removable for spot cleaning. Easy tool-free assembly; interlocking frame components assemble in minutes. Outer frame folds down for compact, convenient shipping to your front door. Twin size measures 5 x 74 x 38 inches (HxLxW) 7 DAY FULL REFUND GUARANTEE ON THIS ITEM IF ANY ISSUE IS FOUND THAT WAS NOT DESCRIBED/PICTURED. 7 DAY STORAGE IS ALSO AVAILABLE. SEE NOTES TO BIDDER, IN AUCTION DETAILS, AT THE TOP OF PAGE 1 FOR MORE INFO.