One layers of bias sisal sewed with two layers of cotton cloth, provides it good cutting and polishing properties, mainly used for pre-polishing metal ware. They are two types of OS: A. With dip treatment in special resin; harder buff, better cutting power, extremely long service life, self-cooling druing operation. B. Without dip treatment in special resin, softer buff, saving polishing compounds, self-cooling during operation. Diameter: 100 - 500mm Width: 15 - 25mm Hole: as your requested.