Silentnights market leading 2016 visco elastic memory foam mattress is one of the thickest on the market with an overall depth of 18cmour silentnight memory 3 zone mattress reacts to your body temperature to soften the mattress where needed providing a unique mould to your body contour the silentnight memory foam evenly distributes your body weight which in turn greatly reduces pressure on vital points of the back hips and shoulders resulting in a relaxed and undisturbed sleepsilentnights secret