Porter Cable, 20V, Max, Lithium-Ion, 1/2" Impact Wrench, Up To 330 FT/LB Maximum Torque, Multi-Speed Control For A Variety Of Applications 0-1,700 RPM, 1/2" Anvil With Detent Pin, LED Light With 20 Second Delay For Increased Visibility, Includes: 20V Max Lithium Ion 4.0Ah Battery Pack.