The SAS Cool Step - #2 Comfort Footbed Replacement Insole comes in 3 size widths (S - N), (M), (W - WW). (S -N): fits either a Slim or Narrow shoe. (M): recommended for medium width shoes. (W - WW): fits either a Wide or a Double Wide shoe. NOTE: This is the original SAS replacement insole that is recommended for the following SAS women's styles: Roamer, Viva, Clog, Twin, Willow, Crissy, Clog Non Slip. The SAS Cool Step Footbed uses a germ-fighting foam material that aids in wicking moisture from the foot's surface. Cool Step O2 foam is engineered to be firmer and more supportive under the heel for stability and softer under the forepart of your foot for cushioning. The O2 Airflow cover on this helps in reducing friction that can cause heat buildup underfoot. The heel is cupped for a cradle-fit. The SAS Cool Step Footbed gives the wearer a much 'cooler', more stable, comfortable walking experience. Machine washable. Made in the USA.