Sierra Sleep 13 Inch Hybrid Hot Buy M20741 King MattressWith this hybrid king mattress, you have endless possibilities for restful sleep. Feel the support of a truly traditional coil mattress which contours to your body for a comforting feel. High density foam provides the firmness you love. Convoluted comfort foam provides added air flow, keeping you cool and comfortable while alleviating aches and pains. This mattress arrives in a box for quick and easy setup. Simply remove the plastic wrap and unroll.