3kHz 39.5×20mm Alarm Buzzer with 89dB

The BJ4020 Piezo Alarm Buzzer is a high-performance passive piezoelectric alarm buzzer designed for industrial warning systems, equipment fault alerts, and safety notification applications.   Featuring a high-quality piezo ceramic element and durable black PPO housing, the BJ4020 delivers stable and clear alarm sounds even in demanding industrial environments. With a wide operating voltage range of 1~25Vp-p, a resonant frequency of 3000Hz, and a minimum sound pressure level of 89dB at 30cm, it provides reliable audio feedback for various electronic devices and control systems.   Its compact through-hole design, excellent temperature resistance, and proven reliability make it an ideal choice for industrial control panels, security systems, automation equipment, medical devices, home appliances, and safety alarm applications.   Dimensions Electrical And Acoustical Measuring Condition Frequency Response     3Vp-p 50% duty Square wave,30cm