The size of styrofoam is 23.6 x 17.7 x 0.6 inches (600 x 450 x 15 mm) thick and comes in a pack Hardness is classified as normal hardness, medium hardness, and high hardness. This product has a medium hardness (medium hardness) 60 times the foam magnification and feels firm on the skin. Many used in DYI, craft and modeling.