2.3mm 6 rings spring high manganese carbon steel,heat monlding,natural palm ... the mattress:1.It is dia 2.3mm 6 rings spring adopt high manganese carbon steel, ring around each other ... moisture.anti-bacteria and acarid3. Half palm mix half spring, so one side is hard the other is soft, ... you like.4. The upholstery is excellent knitted cotton fabric, anti-bacteria and acarid.5. It is Mini disconnected ...