An electric toothbrush may be provided by combining an attachment part (3) for an electric toothbrush (1) such as an attachable brush head and a handle section (2). The attachment part (3) has a tubular connecting piece adapted to be connected to a neck (4) of a handle section (2) of the toothbrush (1), wherein the connecting piece (7) has an inner and outer tubular structure forming a double-cone comprising an inner and an outer conical surface that face each other and that define an essentially ring-shaped groove there between, wherein the inner and outer conical surfaces are adapted to be engaged with inner and outer conical surfaces of the neck (4) of the handle section (2).
