The Sareer Memory Foam Gel Foam Matrah Mattress made by the NBF-approved Sareer team features a 12.5cm layer of memory foam & a 2.5cm layer of gel foam. The foam layers, combined with a luxurious quilted cover, mould to your body's natural sleeping position & also regulates temperature & humidity, maintaining a pleasant sleeping environment throughout the night. * For health & hygiene reasons, we are unable to offer refunds or exchanges on mattresses unless they are returned unused & in their original packaging. For more information please see our Easy Returns section. For more information on different mattress types, please visit our Mattress buying guide. [ Click here for more information.] (https://www.dunelm.com/info/buying-guides/mattresses-&-mattress-toppers-buying-guide)[ Click here] (https://www.dunelm.com/infodocs/downloads/ Furniture-Sizing-Guide.pdf) to check out our handy sizing guide to help you find out if you’ll be able to get your new mattress into your home.