Features: Design for DIY projects, this 3.3-5V buzzer module supports both passive high level triggering operation and active buzzer compatibility, delivering versatilitys audios signaling solution with clear 70dB+ output. Features compactly design with mounting hole, drive by 9012 technology for precise square waves input (2K-5KHz) without builts in oscillation. Ideal for electronics hobbyists, robotics engineers, and STEM educators requiring reliable alarm systems or programmable tone generation. Enhances security setups, IoT devices, and DIY prototypes with its high level triggering responsiveness and testing capabilities. Builts with durability components and standardized pin definitions (VCC/GND/I/O), it ensures stable performances in automation controls, educational lab, and embedde system integrations. Specifications: Composition:Plastic Size:Approx.3.2x1.3cm/1.25x0.51inch Working voltages: DC3.3 V to 5V Applicable scenario:Alarm system Package Includes: Package A 2pcs Buzzer Module Package B 5pcs Buzzer Module note: Please allow 1-2cm errors due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual item color.