The 3500 Sovereign Mattress is a Medium Firm feel and is approximately 28cm in depth, this is an extremely highly rated premium mattress and from the first use you will notice a difference in quality and design. The mattress is made from a high count of premium fabric encased pocket springs, double support memory foam layers, reflex foam as well as greater edge support. Redefined Comfort: Double memory foam design is what sets this mattress apart from the rest, by using support memory foam under the normal memory foam layer we have ensured the mattress better conforms to your body shape, providing extra comfort and greater support than traditional memory foam mattresses. Reflex foam offers rebound support to allow for greater spinal alignment and further aid with relieving pressure. Undisturbed Sleep: 9-Zone pocket springs ensure you can roll around freely across the mattress during your sleep as they work individually in the areas where pressure is applied, perfect for those with partners or pets. Somnior Beds Mattress Size: Small Double (4')