DEWALT 20V MAX Impact Wrench, Cordless 2-Tool Combo Kit, 1/2-Inch Mid-Range and 3/8-inch Compact with 5ah Battery and Charger (DCK205P1) - Amazon.com
Milwaukee M18 FUEL 18V Lithium-Ion Brushless Cordless 1/2 in. Impact Wrench with Friction Ring (Tool-Only) 2767-20 - The Home Depot
Impact Driver vs Drill: What's the Difference? - Pro Tool Reviews
Impact wrench - Wikipedia
Seesii Brushless Power Impact Wrench, Cordless, 1/2 inch Max High Torque 479 Ft-lbs(650Nm), 3300RPM w/ 2x 4.0 Battery, 6 Sockets,9 Drill,6 Screws for Car Home, WH700 - Amazon.com