A snowboar is a thin, hourglass shaped board ridden down a sloped section of earth covered in snow. It is often thought of as the winter equivalent of a surfboard or skateboard, except that the rider's feet are bound to the board via bindings. Snowboards generally have a length between 140-165cm and a width between 24 and 27 cm. The size variants are to accommodate the many varieties of people, skill levels, snow types, and riding styles that exist within the activity known as snowboarding. Snowboards are usually constructed with a laminated wood core sandwiched between multiple layers of fiberglass. The bottom or 'base' of the snowboard is generally made of various constructions of plastic, and is surrounded by a thin strip of steel, known as the 'edge'. The top layer, where a printed graphic usually resides, is usually made of Acrylic.