Very unusual US scale covered under glass and wood. The scale is constructed with tensioned bands instead of knife edges or other bearings. Pivoting is achieved by the torsional twisting of the steel band. This kind of scale exist in different sizes and also covered in a wooden case or in a iron, chromed - glass case. The table is often marble of black colored glass. This big ( 24" ) scale with cut glass is harder to find and is very heavy. (near 20 KG)