The top layer of the mattress contains 5cm 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 15cm layer of firmer reflex foam used to provide additional support and giving the memory foam its natural orthopaedic properties 5cm of slow recovery memory foam 15cm of firmer reflex foam no need to turn edge to edge suppo