The DeWalt D51321 is a 3/4-Inch to 1-3/4 Inch Heavy-Duty Coil Roofing Nailer. The tool is packaged in a lightweight (4.9 lbs) magnesium housing that delivers enhanced maneuverability and minimizes user fatigue. Unique features highlighted by the pneumatic bias feed piston, a compression spring feed pawl support and a patented double o-ring support on the feed piston provide unmatched reliability. Ease of use features such as tool-free depth adjustment, integrated nose door jam clear, an external nail height adjustment lever and a hinged feed piston cover greatly reduce downtime. The easy-to-use tool-free depth adjustment is located by the trigger, providing a cleaner nose area for more exact fastener placement.