DEWALT DCF899P2-20V MAX* XR Brushless High Torque 1/2" Impact Wrench Kit w/Detent Anvil Maximum initial battery voltage (measured without a workload) is 20 volts. Nominal voltage is 18.
DEWALT 20-volt Max Variable Speed Cordless Impact Driver (1-Battery Included) in the Impact Drivers department at Lowes.com