An apparatus for receiving operationally powering units interchangeable grooming units. The apparatus comprising a casing, a motor, attachment means for allowing the grooming units to be releasably attached to the casing and mounting means for allowing the grooming units to be driven by the motor. The mounting means comprise a shaft with an end portion having a protrusion located eccentrically on the end portion. The mounting means are adapted to enable the grooming units with accordingly adapted receiving means to carry out a rotational movement and/or a linear movement without gear arrangements in the receiving means of the grooming unit.