... 3.UL,FCC certification 4.1 year warranty Upgraded torque pneumatic automatic screw driver(double-headed) Advantage:(different from other ... other screws intensive product Function 1. Automatic screw columns, feeding, automatic screening of special-shaped screws,automatic supply air ... locking quality6.Compact, transmission distance is 4 meters, the machine can be placed in working on stage,save space7. ...