Milwaukee m18 biw38 compact 38in impact wrench measures 152mm in length making it perfect for working in confined spaces with a heavy duty full metal gear box and gears for superior durability and maximum torque with redlink overload protection electronics in the tool and battery pack it delivers best in class system durability also has an on board fuel gauge and led light redlithium ion batteries deliver two times more run time up to 20 more power and two times more battery life the battery a