The Bosch MRF01 fixed base is designed exclusively for use with Bosch MR23EVS router motor. It features a trigger-controlled power switch in the right handle, so you don't have to reach up to a switch on the motor to turn the tool on and off.
This offset base for Bosch Colt palm routers allows you to rout near vertical surfaces, such as laminate applied to the top of a countertop backsplash.