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.