Best in Class Air Volume*1: With the optimized air duct structure, the RB18DC is more powerful than its predecessor and provides the best in class air volume, allowing the user to get the job done more quickly. Easy Air Volume Control: The variable speed trigger and three air volume settings allow the user to control the volume with ease to suit the application. Lock-on Button: For continuous use. Low Vibration: The RB18DC features 25% lower vibration than its predecessor, ensuring less fatigue and comfort for the user.