【Material and Construction】The top green tea AeroFusion memory foam will make your breath fresher, the second-floor liquid gel flex foam can adjust the temperature and make you feel cooler, and the high-density flex support base foam for ultimate comfort. 【Health and Safety】All foam has been certified by CertiPUR-US without harmful substances like formaldehyde, mercury, and other heavy metals. The mattresses use fiberglass-free and flame-retardant inner covers. 【Comfortable and Medium Firm】Medium firmness is designed for every kind of sleeper and conforms to every curve, whether you're a side sleeper, back sleeper, stomach sleeper, or someone who tosses and turns. The mattresses offer the optimal level of firmness, coolness, breathability, and comfort.