A reusable drug delivery device for selecting and dispensing a number of user variable doses of a medicament, comprising a housing (10, 20), a cartridge holder for retaining a cartridge containing the medicament, a piston rod displaceable relative to the cartridge holder, a driver coupled to the piston rod, a display member for indicating a set dose and being coupled to the housing (10, 20) and to the driver, a clutch for rotationally coupling the driver to the housing (10, 20) or the display member and a button rotationally coupled to the clutch and to the driver, characterized in that the drug delivery device comprises the following features: - the driver is in threaded engagement with the piston rod, permanently rotationally locked to the button, axially displaceable relative to the button and comprises at least two separate components (41, 42) which are rotationally coupled during dose setting and during dose dispensing and which are rotationally decoupled during resetting of the device, - the display member has a distal end provided with an inwardly protruding thread and a proximal end provided with an inwardly protruding flange, wherein the display member comprises two separate components (61, 62) with a first component comprising the thread and the other component comprising the flange, - the button comprises fingers which engage corresponding slots of the driver for rotationally coupling the button to the driver and which comprise snap features engaging corresponding snap features of the clutch for axially coupling the button to the clutch, - the driver comprises fingers which engage corresponding slots of the button for rotationally coupling the button to the driver and which comprise hook features engaging corresponding contact features of the display member for axially coupling the driver to the display member, - the button comprises a ring of clicker teeth engaging a corresponding clicker feature of the display member at least during dose dispensing. - the driver is in threaded engagement with the piston rod, permanently rotationally locked to the button, axially displaceable relative to the button and comprises at least two separate components (41, 42) which are rotationally coupled during dose setting and during dose dispensing and which are rotationally decoupled during resetting of the device, - the display member has a distal end provided with an inwardly protruding thread and a proximal end provided with an inwardly protruding flange, wherein the display member comprises two separate components (61, 62) with a first component comprising the thread and the other component comprising the flange, - the button comprises fingers which engage corresponding slots of the driver for rotationally coupling the button to the driver and which comprise snap features engaging corresponding snap features of the clutch for axially coupling the button to the clutch, - the driver comprises fingers which engage corresponding slots of the button for rotationally coupling the button to the driver and which comprise hook features engaging corresponding contact features of the display member for axially coupling the driver to the display member, - the button comprises a ring of clicker teeth engaging a corresponding clicker feature of the display member at least during dose dispensing.