Microfiber is a Synthetic material typically used in the manufacture of apparel. The most common Microfibers are polyester and nylon.
About Slippers:
A type of shoe typically designed for indoor use that can be a variety of styles, including slides, mocassins, scuffs, booties, thongs, or loafers. Usually the uppers are made of soft leather or other fabrics (as opposed to tougher fabrics like hard leather that regular shoes are made of) and are sometimes lined with soft materials like felt, shearling or wool.