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