World's Softest Socks Cozy Slippers (Black Dots, Medium / 7.5-9) Imported Acrylic blend surrounds your feet with luxurious softness. Foam-padded sole adds an extra level of comfort. Non-slip bottom helps keep you confident on your feet. Durable nylon gives the slippers stretch for a comfortable fit. Non-binding topline stretches and conforms to the top of your foot.