Magnetic Buzzer With Circuit: -9*4.5mm, 2700Hz, 3VDC; -Self drive with internal oscillator circuit; -ISO, RoHS, Reach. Magnetic Buzzer application:-Mobile phones, Computers, White goods, Medical equipment, Alarm system.Main feature: (9*4.5mm, 2700Hz, 3VDC)-Small size;-High sound pressure;-Not allowed for wave soldering. 9*4.5mm Magnetic Buzzer