THE FUTON SHOP 8" LIQUID SKY CALIFORNIA KING SIZE GEL SOY MEMORY FOAM COTTON MATTRESS Cooling gel soy hybrid memory foam Bioflex hybrid foam from Soybeans - mattress foam is made partially from soy bean oil, Soft density 4 inch Foam Core - 24 ILD - 1.85 Density 8-inch Medium Firm futon or bed mattress. Natural Egyptian Staple Cotton Grown in America.