This grinding head has 8 different granularities for materials. The original brightness of the working surface to be polished is grade 4.With the steadily improving granularitythe brightness of the working surface polished can reach grade 12.After being polished by the grinding heads,The grind head of each grade grain size can reach the surface of clearness as follows(Only for reference):80#▽5（rough grinding）,120#▽6（rough grinding）,240#▽7（half refined grinding）,320#▽8（refined grinding）,600#▽9（super fefined grinding）,800#▽10（rubbing grinding）,1200#▽11（refined rubbing grinding）, 1500#▽12 （mirror polishing）.