The king size zen ergopedic memory foam mattress is our bestselling mattress for those who require additional support yet want to retain high levels of comfortr designed with a 5cm dual hd memory foam layer the mid layer acts as a lumber support with a softer top layer providing sumptuous comfort this memory foam layer moulds to your body shape during the night helping to alleviate aches and pains as you sleep r the zen ergopedic memory foam mattress base consists of superior medical grade