Features: * clog free * achieve consistent surface finishing * long polishing lifespan * reduces burn mark on the articles by its own air-cooling action * easily to modify, so sanding along to concaved (or convexed) surface is available * reliable safety at high speed is obtained from careful measurement and adjustment for well-balance. * importance of good balanced flap wheels lead to longer operation life of polishing machines * specially reinforced inside of big flap wheel with back-up nets * simple fixing and removing * does not require skilled worker to handle * overall improve polishing costs.