The Glenville mattress is categorised as an orthopaedic mattress due to the fact that it contains a firm orthopaedic spring system. While this spring system does provide a high level of back support it does not mean that the mattress is too firm because it also contains extra thick comfort layers. On top of the springs are layers of hypoallergenic polyester which give the mattress a very high loft appearance & provide a sleeping surface which you can sink into a get an excellent level of luxury. Mattress is 26cm deep Supportive orthopaedic spring system Deep hypoallergenic comfort layers High loft quilted finish Handles for easy turning Vents for air flow & ventilation Free delivery