This Bosch 18-volt cordless combo kit is a convenient package with 2 powerful cordless tools. Included in this kit is the Brushless 1/4 in. and 1/2 in. Socket-Ready Impact Driver and Brushless Compact Tough 1/2 in. Hammer Drill/Driver. The Brushless 1/4 in. and 1/2 in. Socket-Ready Impact Driver is able to switch from 1/4 in. screwdriver bits to 1/2 in. sockets for the convenience of an all-in-one tool. It provides contractors, carpenters and other pros with an unmatched solution to get the job done efficiently. The Brushless Compact Tough 1/2 in. Hammer Drill/Driver features kick-back control, which reduces the risk of sudden tool reactions in binding conditions. This integrated acceleration sensor automatically shuts the tool down when a potentially dangerous rotational torque reaction occurs in a bind-up scenario. The hammer drill/driver is engineered with an upgraded heavy-duty all-metal chuck and an efficient brushless motor.