Engineered wood frame. Plastic shadowline support legs. High-gauge sinuous springs provide seat cushion support. Webbed back cushion support. Seat cushions have fiber-wrapped, high-resiliency polyurethane foam cores. Seat firmness: Medium. On a scale from 1 to 5 (5 being firmest), we rate it a 4. Back cushions are fiber filled. Loose, reversible back cushions with zip-off covers; seat cushion is attached. Trundle pulls out from sofa and lifts up via elastic strap to create a Queen-sized sleeping area. This contract-grade item is manufactured to meet the demands of commercial use in addition to residential. See more. Made in Thailand. Patent pending.