Bosch Angle Grinder GWX18V 50PCN 5 Inch Bare Tool X LOCK Brushless (18V DC Paddle Switch Electronic KickBack Drop Control Metal Shearing) pump Segmented Air Cooling Rim: Perimeter expansion Segmented Air Cooling Rim: Perimeter expansion slots and deep gullets channel air and water directly to the cut line to flush abrasive swarf and prevent overheating 500 RPM to deliver high cutterhead speed and extended battery runtime this cordless unit incorporates the keyless X LOCK mount mechanism allowing wheel changes up to five times faster than traditional spanner wrench systems Equipped with an emergency non locking paddle switch