The Eve Mattress, Queen The World's Most Comfortable Mattress Crafted by a team of mattress experts and leading British designers The best of luxury memory foam and high resilience foam, giving you comfort, coolness and bounce Free delivery, 100 day trial, 10 year warranty Eve can function on any bed base, however we recommend you use it with slatted bases to really benefit from its amazing properties. If a slatted base is being used, we recommend that the gaps do not exceed 7cm, it is also important that slats are secured, evenly spaced and rigid.