Shop now at Mattress Store! Personalized Comfort: With the M3’s interchangeable coil units, both partners choose their preferred firmness for their side of the bed—and can change it at any time. Cooler Sleep: No more waking up hot in the middle of the night. The M3’s instant-cooling cover helps your body maintain a cooler resting temperature for deeper, more refreshing sleep. Easy to Clean: The M3’s removable cover is machine-washable, and the modular design allows for easy access to vacuum the