PUX can be worn over a bare foot or over a sock but not designed to be worn in a shoe.Made from durable, comfortable EVA material allowing the PUX to be work indoors or outdoors.Available in two sizes – Small/Medium #BH7000SM for shoe size small than size 8 and Medium/Large #BH7000ML for shoe sizes 8 and larger.Package contains two PUX units and both are universal shaped to fit either foot.Easy to clean with water and soap and let air dry.