The Bosch GWS18V-10N 18V Brushless 4-1/2 – 5 In. Angle Grinder is an ergonomic, robust grinder that is engineered with a narrow grip zone for best user comfort and considerable power. It delivers the ultimate combination of performance, control, and power in a cordless grinder. The grinder’s brushless motor provides power equivalent to a 10-amp corded grinder and greater efficiency that maximizes runtime and productivity. The grinder has a brake system, which helps provide a rapid stop of the wheel when the switch is turned off. It also includes other advanced electronics such as drop control, KickBack Control, restart protection, and constant electronics for constant speed under load. It has a lock-on/off slide switch for extended-use applications and an updated gearhead mounting collar that's now compatible with all Bosch metal and concrete guards.