Bosch CLPK233-181 18V Premium Brushless Lithium-Ion Drill/Driver and Impact Driver Combo Kit IDH182  1/4-Inch and 1/2-Inch Socket-Ready Impact Driver is most powerful in class IDH182  Quick-change socket-ready adapter for 1/4-Inch hex and 1/2-Inch square drive DDS182  Maintenance-free, Open-Frame EC Brushless motor DDS182  Delivers 442-Inch-Lbs. of torque and no-load 1,700 RPM drill speed IDH182  Hassle-free EC Brushless motor