Our Acesleep Mattress Review found there are 4 layers of memory foam under the cover. The top layer is an open celled, plant based memory foam 2.5 inch layer. Open celled, plant based memory foam sleeps 25% cooler than traditional petroleum based polyurethane. Under the open celled foam layer is a 2 inch layer of bamboo memory foam. In addition to temperature regulation, the bamboo charcoal infused foam is antimicrobial and dust mite resistant. The 3rdlayer of the Acesleep Mattress consists of 1.5 inches of gel infused memory foam. Gel infused memory foam manages temperature by transmitting excess heat. This breathable layer also provides contour and pressure relief on key parts of your body. The 4thlayer of high density base foam is 6 inches thick. High quality base foam is crucial to long term support and the overall durability of your mattress.