It is very easy to operate 35mm slide projector 24V/250W halogen lamp medium & high lumens and efficient cooling system. It is used in Conference Rooms, Training Centres, Educational Institutions and many other stage show. Constructed with aluminium & mild steel and good electronic component.Microphone Sensitivity 72dBFrequency Response 100 to 1000Hz.Output Impedemce 600OhmsPacked in cardboard with vinyl cover.