Bosch Power Tools deliver stronger performance and lasting reliability. The Bosch 1900 series 7 In. and 9 In. grinders are redefining innovation. The line is powered by A new, ultra-efficient 4 HP motor. It utilizes the best vibration control system on the market. If that isn't enough, they are also the lightest large angle grinders available, weighing up to 20% less than any comparable competitive model.