1. Include standard reaming shells, backend reaming shells, two ring reaming shells and carbide locking couplings. 2. Natural diamond reaming shells, synthetic diamond impregnated reaming shells and PCD surface-set reaming shells. 3.Resistant matrix and good for different types of grounds. 4. The size of reaming shells : AQ, BQ, NQ, NQ3, HQ, HQ3, PQ,