Abstract: A hairdryer includes a casing having a main body having a main through cavity containing an electric motor and a fan to generate an air flow with a settled speed; an inner diffuser inside the main through cavity at the front outlet opening of main body and includes a through cavity having a passage section decreasing towards the front outlet opening to increase the speed of the air flow; the main body includes at least one side opening at the front outlet opening to enable air from outside entering into the main through cavity to increase an air output flow rate from the front outlet opening; an outer outlet element is reversibly coupled to the front outlet opening and includes an outflow tubular portion and a coupling tubular portion inserted into the front outlet opening to close the side opening and prevent the air from entering the main through cavity.