This innerspring mattress is more than a mattress, it€s a haven for deep, restorative sleep that inspires your senses. This innerspring mattress experience goes beyond mere comfort. It creates a restful escape where sleep is the ultimate luxury. This innerspring mattress now includes a sleep tracker pending mail-in rebate. Once your L-Class Beautyrest Black 14" Extra Firm Innerspring Mattress is delivered, go to beautyrestpromo.com, enter the serial number found on the law tag of your innerspring mattress or on the frame of your adjustable base to redeem your free Beautyrest sleeptracker monitor. The Beautyrest sleeptracker monitor is a fully integrated, wearable-free system designed to continuously monitor all stages of your nighttime activity. The highly accurate sensors, powerful processor and intuitive app collect and process the information on heart rate, respiration rate, and movement. The results are tailored reports that reveal insights into individual sleep behavior, helping you achieve optimal next-day performance. Mattress Size: King