Electric toothbrush comprising a housing, and a replaceable brush head that is mounted or mountable on the housing, where-in in the housing a motor and a battery unit is provided as well as a transmission between the motor and the brush head, and wherein the brush head, the transmission, and the motor are essentially built in-line, and the battery unit or units is/are positioned in the housing next or adjacent to the motor and/or transmission and parallel to the built in-line brush head, transmission, and motor.
