When it comes to your comfort chime in for the Sierra Sleep Chime Express California king mattress. Its memory foam layer contours to your body delivering amazing pressure relief to the bodys major pressure points. This layer is supported by a thick layer of high density support foam which helps reduce motion transfer so you can enjoy an undisturbed nights sleep. Plus this mattress is made of hypoallergenic material which helps those who have allergies. Dust mites pollen mold and pet dander have a harder time finding their way in. This mattress arrives in a box for easy set up. Simply cut away the thick plastic wrap unroll the mattress and watch it fully expand into place within minutes. Folding power basebox foundation available sold separately.