Hercules 20V Brushless Cordless 3/8 in. Compact 3-Speed Impact Wrench – Tool Only - Delivers up to 525 ft. lbs. breakaway torque and 229 ft. lbs. of fastening torque - Amazon.com
Milwaukee M12 FUEL 12 Volt Lithium-Ion Brushless 3/8 In. Stubby Cordless Impact Wrench Kit - Power Townsend Company
Milwaukee M18 FUEL GEN-3 18V Lithium-Ion Brushless Cordless 3/8 in. Compact Impact Wrench with Impact Socket Set (12-Piece) 2854-20-49-66-7005 - The Home Depot