These three-layer insoles begin with a durable top section that wicks away moisture and refuses to emit odor. It sits atop a 4mm high density moldable foam, that quickly takes on your foot shape. Below that, we've incorporated a firm, supportive base layer to keep your arch and heel stable... and you on your feet all day long. Mens shoe sizes- Small(5-6.5), Medium(7-8.5), Large(9-10.5), XL(11-12), XXL(13-14), XXXL(15-16) Womens shoe sizes- Small(6-7.5), Medium(8-9.5), Large(10-11)