The top layer of the mattress contains 25cm of temperature sensitive visco elastic memory foam the visco elastic provides comfort total body support and pressure relief the memory foam also has an open cell structure which enables the mattress to breathe the bottom is a 175cm layer of firmer reflex foam used to provide additional support and giving the memory foam its natural orthopaedic propertiesthis mattress comes complete with a non quilted mattress covervacuum packed for easy trans