Machine Washable - Average Lifespan 6 to 12 Months ASTM Safety Rated for Traction Made in the USA - Quality Workmanship No Wet or Dirty Tracks - Moisture Barrier Inside Four Sizes Available for Shoes 4 to 17 for Men & Women - See Sizing Below SIZING INFO: There are four sizes to ensure a great fit. SMALL: women size 8 and below. MEDIUM: men 7 to 10 and women 8.5 to 10.5. LARGE: men 10.5 to 13 and women 11+. X-LARGE: men 13.5 to 17. This sizing is appropriate for most shoes and bulky work boots. Please contact us if you would like assistance determining the correct size. The material used on the upper portion of the shoe cover is a sturdy nylon with a permanent interior finish that will contain moisture and dirt on your shoes. This same fabric is used to manufacture items such as luggage and tarps. The black soles are durable and extremely nonskid. They will not leave black marks on flooring.