Abstract: A diffuser for air conditioning equipments comprising in combination a stationary outer casing, destined to be mounted at the outlet from the air duct, a shaped diffuser disc carried by a hub mounted by a quick coupling system inside of said casing and co-axial therewith, means for adjusting at will the position of said diffuser disc with respect to the stationary casing in order to adjust the direction of the air flow, and a cylindrical element controllably axially slidable between the diffuser and the stationary body, in order to adjust the rate of flow.