Bosch CLPK245-181 18-volt Lithium-Ion 2-Tool Combo Kit with 1/2-Inch Hammer Drill/Driver, 1/4-Inch Impact Driver, 2 4.0Ah Batteries, Charger and Case 4-Pole High Performance Motor: For maximum power in the most compact size New Patented Gear Train and Clutch: Enables most compact design in its class and lightest weight New Ergonomic Design: Modified orientation relative to handle enables better gripping and increased comfort Most compact impactor design with a head length of 5.4-Inch, allowing the tool to be used in tight and hard to reach places with increased comfort Electronic Cell Protection (ECP): Increases battery lifetime by preventing damage caused by misuse