A nozzle unit for a reaction molding machine, comprising an inlet channel prepared for connection to a mixing head outlet and comprising a first dispensing nozzle, which is prepared for applying a reactive mixture and which is connected to the inlet channel in a first operating state, a second dispensing nozzle being present, which is connected to the inlet channel in a second operating state and which is likewise prepared for applying a reactive mixture. Further disclosed is a mixing head device for a reaction molding machine having the nozzle unit, to a reaction molding machine having the mixing head device, and to a method for producing a plastic part.