Arbors make great starter units and cabochon machines. If you want to build your own custom machine, then an arbor is exactly what you need. Arbors are six wheel units and come with 3/4″ threaded shafts that accept 1/4 -20 screw-on discs or polishing heads. The hoods are removable for easy access. Each unit comes complete with the following; spacers, shaft nuts, pulleys, drive belt, drain tube, drain plug, brass valve, hex nuts and wheel flanges. Motor is NOT included. Arbors are shipped in one box: 27″ L x 17″ W x 11″ H, 33lbs.