Features Reliable Alarm Activation - The internal oscillation source ensures instant alarm activation upon power, providing immediate alerts for your projects Easy Program Control - Designed for seamless integration with microcontrollers, this module allows for straightforward sound control at high and low levels Durable Transistor Drive - Powered by a robust 9012 transistor, this module delivers consistent performance and reliability in various applications Simple Installation - Features pre-drilled holes for easy mounting with bolts, making installation quick and hassle-free for any project Versatile Voltage Compatibility - Connect directly to both 5V and 3.3V microcontrollers, offering flexibility for a wide range of electronic devices and toys Features: 1、This active buzzer has internal oscillation source, so it will alarm as long as being energized. 2、Convenient program control, single chip microcomputer high and low level can make it sound, better than a passive buzzer. 3、Module is driven with 9012 transistor. 4、Designed with holes for fixing with bolt, convenient to install. 5、External connection of 3.3V-5V voltage, can be directly connected to 5V micro-controller and 3.3V micro-controller. Specification: Features: This active buzzer has internal oscillation source, so it will alarm as long as being energized. Convenient program control, single chip microcomputer high and low level can make it sound, better than a passive buzzer. Module is driven with 9012 transistor. Designed with holes for fixing with bolt, convenient to install. External connection of 3.3V-5V voltage, can be directly connected to 5V micro-controller and 3.3V micro-controller. External connection of GND3 out external micro-controller IO port. Specification: Working Voltage: 3.3V-5V Module Interface: 3 wire system Size: 3.8*1.3cm/1.5*0.5in Quantity: 5pcs Weight: 4g(approx.) Package Includes: 5 x Buzzer Modules Package List