... .Simpie structure,easy operation,little maintanence.Widely used in the hole drolling for water or gas drainage in the coal mine ... inmaintanencePowered dy compressed air,no explosion,more safe.Pneumatic Manual Drilling Machine With a Suppoter Main SpecificationsTypeZQSJ-100/2.5Working PressureMpa0.5Rated ... )100Sound Power leveldB(A)120Drilltail Size(mm) Weightkg25 Pneumatic Manual Drilling Machine