ZQSJ-90/2.1 pneumatic handheld rig for support in coal roadway in coal roadway, half of drainage gas used during the operation. ZQSJ-90/2.1 live support pneumatic hand-held drill for a portable, light weight, easy to move, reliability, simple operation, easy maintenance, high efficiency drilling characteristics, but also has the reverse function, you can put the exit hole, and it is ideal equipment for a well draining tile job.