Polyester INCREASED SOFTNESS AND COMFORT WITH IMPROVED SLEEP QUALITY - A comfortable mattress is essential for quality sleep, and while replacing a mattress can be expensive, a mattress topper is an affordable solution. The Novilla mattress topper is a perfect addition to an old mattress, adding softness and providing extra support. The CertiPUR-US certified foam and OEKO-TEX bamboo charcoal cover meet specific standards for a more comfortable and restful night's sleep. PRESSURE RELIEF & COOLER RESTFUL SLEEP - Our 4-inch mattress toppers utilizes a 2-Layer design. Includes 1.5" cooling gel memory foam & 2.5" bamboo charcoal foam. High-density Memory foam actively contours to your body curve to align the spine and relieve pressure point aches and pain, preventing you from sinking into foam. Open cell & egg crate foam structure design improves airflow and breathability, regulates temperature & prevents overheating for better sleep.