Tyvek FC skid-resistant shoe covers 18″ high (intended to be worn over your own shoes). Tyvek spunbonded olefin is a unique nonwoven material. Resistant to penetration it is chemically and biologically inert low linting and static free until laundered. A serged seam is produced when three threads are interlocked around the raw edges of two pieces of material for a strong stress-resistant seam.