Amazon.com: UltraBlock 100% Waterproof Mattress Protector, Luxuriously Soft and Comfortable, Fitted Fit for Full Size Futon Mattresses Up to 12" Thick, Breathable, Washable : Home & Kitchen
Amazon.com: NAGI Japanese Futon Mattress Traditional Japanese Floor Mattress Shikibuton, Twin Size (39”x79”x2.7”) : Home & Kitchen
Futonland – Sizing Charts for Mattresses and Futon
708 - Innerspring Comfort Coil Futon Mattress - Futon World