Sleep Joy 4" Memory Foam Mattress Topper made with Biofresh, 5-year Warranty, California King 4 Inch of premium soft and conforming Bio fresh memory foam provides cradling comfort and relieves pressure points Through a unique production process, foam odor is eliminated Allover ventilation allows for high airflow that wicks away heat and moisture for a cooler, more hygienic sleeping environment Open-cell construction offers superior durability that retains its shape over time and outlasts the competition Sleep Joy memory foam is made in the USA