4.5A/500W powerful Motor Variable Speed with Reversible The Adjustment Function of Countersink by Turning the Depth Adjustment Tumbwheel Remove the Fasterner from the Machine, It is Electric Drill. Two Function:Electric Screw Drive & Drill. Screw Size:25mm(1??) to 45mm(1-3/4??) When Screwing,the Screw Can Be Automatic Moving. This Tools with Drilling & Screwing Function have Automatic Transfer the Screw when Operating,This is the Best Screw Tools for the Roof in Home