Abstract: An exterior rear view mirror assembly has a base member adapted to be fixed to the body of a vehicle and carrying a first detent formation located at a predetermined radius from a substantially vertical axis. A mirror support member is mounted on the base member for angular movement about this vertical axis. A detent carrier which is also angularly movable about said vertical axis, carries a second detent formation confronting said first detent formation at the same radius from said vertical axis. Clamping means are arranged to secure the detent carrier to the mirror support member at a selected one of a multiplicity of orientations relative thereto.