Bosch GWS18V-45B15 4-1/2" Angle Grinder 18V with 4.0 Ah Core Battery is a portable cordless grinder designed for professionals who need reliable power. It features a four-brush motor design and optimized gear structure. The grinder is powerful, producing 10,000 no-load rpm, to handle professional cutting and grinding applications. It features a two-position Vibration Control side handle for better handling and less operator fatigue. It is designed for long tool life, with an optimized brush design. It is engineered with a quick-change, burst-resistant wheel guard and restart protection to avoid accidental startup. The kit includes a next-gen CORE18V 4.0 Ah Compact Battery, which delivers light weight and high power, and it is equipped with CoolPack technology for extended life. Using 21700 cell technology, the CORE18V exceeds the power of the original two-layer 4.0 Ah battery with half the number of cells.