Casper Sleep Memory Foam 10 Inch Mattress, Twin XL 4-layer foam construction for support, breathability, and bounce Open-cell hypoallergenic latex keeps you cool all night Please note: Any new product can have a mild scent upon unboxing. Should your Casper mattress have a scent, it will dissipate in a few hours in a well-ventilated room. Also, once you take your mattress out of the box, it will expand and be ready to sleep on within minutes. Please note that some mattresses may take longer to expand.