advantage: 1. good balance 2. sharp fast grinding 3. soft bond ... as granite, marble, natural and artificial stones, etc.2. For grinding, leveling, shaping and polishing stone surface ... 5, 6, 7, 8, 9TypeSingle Row, Double Row, Turbo Row, Radial, SnailConnection22.23mm, 5/8inch -11, M14, ... eluminum; with or without holesDifferent turbo as below:- Sang 4 inch double turbo diamond cup grinder with aluminum ...