8" Sleep Master Spring Mattress & Bi-Fold&reg; Box Spring Set - King Cover is a polyester jacquard with fire barrier Top features quilt and foam padding Durable steel, 12 gauge coils - Pocketed Spring Bi-Fold Box Spring Folding Foundation is made from heavy gauge metal featuring maximum edge firmness. No assembly required- remove from box, unfold, and lay your mattress on top.