Choose Top quality Synthetic diamond powder 10 pcs Segmented Arrow Type Segment Design, Long Life, 7mm Diamond Height Dry or Wet grinding of concrete, granite, stone, marble, tile, masonry and some other construction material to smooth uneven surfaces and remove flashing Suitable for any 7” angle grinders. PLEASE NOTE: These some small holes on the back of cup wheel, that is Dynamic Balance Treated for cup wheel. Every cup wheel must be do Dynamic Balance before out of our factory.