The Imaginarium Fun Mattress 6” Hybrid of Bounce Foam and Coils is a three-layer mattress that is supportive and comfortable and brings bounce back to bedding! The top layer is our specially designed bounce foam that offers comfort and support as this foam is soft, but still has a high responsiveness that allows the foam to bounce back quickly. The second layer is our edge-to-edge mini coils that gives support all the way around the mattress. The hybrid combination of bounce foam and mini coils creates a comfortable supportive sleep experience and gives the Fun Mattress that extra bounce that makes it unique and fun. The third layer is a base foam that gives the mattress stability. The six inch Fun Mattress can also be used with bunk beds. If you loved the Fun Pillow, you're going to love the Fun Mattress!