This mattress has a unique adaptive comfort system. This means that you can tailor your mattress firmness level to your personal wants and needs - within reason that is. Basically we've used 1000 full height springs, designed with a softer side and a firmer side, and wrapped each and every one of them in individual pockets to reduce the likelihood of motion transfer and partner disturbance. - For spring and foam lovers who want a little extra - Our first ever adaptable mattress - Choose from a firmer or softer side - Part springs, part foam, 100% comfy - 28cm deep for seriously good snoozing - Eve The Wunderflip Premium Hybrid Sleep Mattress in White - Size: King