The Earlybird Coppercool Performance 10" Firm Memory Foam California King Mattress pairs firm support with cooling technology to promote a steadier, more restorative night's sleep. Polyurethane memory foam layers deliver responsive, pressure-relieving support while a Coppercool performance layer and cooling cover help manage temperature through the night. It ships as a bed in a box for easier setup and fits most frames; it is compatible with a box spring for added height and support, and is backed by a 10 year warranty and made in the USA for reliable performance.