Mattress spring unit Twin, Full, Queen, King, 288,312,336, 364, 3.0, 3.6, 4.0, 4.6. Steel wire range: 2.0mm ... are metal products manufacturer and exporter in China, we offer spring tines, rubber track, rubber belt and other agri parts for ... , cultivator and other farming equipment. Also,we offer zig zag spring, bonnel spring for sofa , seat, mattress and other furniture.