The Mattress Tilter is used under the mattress at the bottom of the bed to relieve the symptoms of swollen ankles, varicose veins or lower back pain. Alternatively, it can be used under the mattress at the top of the bed to relieve respiratory problems. Size 460×630×130>20mm (18×25 ×5>1"). Made from polyurethane foam. Cover is polyester velour.