Bosch MRF01 Router Fixed Base for MR23-Series Routers Fixed base with fine adjustment knob with on/off switch located in the handle Trigger control system conveniently located in handle for enhanced control Versatile fixed base adjustment system for easy and precise bit depth adjustment Macro and microfine adjustment system with resettable depth indicator Large 3-3/4-Inch base opening and 2-Inch sub-base opening accepts larger bits