The Master II spray gun unit has been engineered to deliver operations that are highly intuitive and easily managed. The main unit may be dismantled manually to supply easy access to the mixing chamber, seals, filters, and check valves. This device is supplied together with a tool kit that is needed for the adjustment and the maintenance of the gun. The rotary head is capable of turning up to 360° and the internal parts of the unit may be serviced without having to remove the coupling block from the unit. Moreover, this device is designed in such a way that the air cylinder and the trigger valve is protected from interference.