Package includes: 3 pcs Active Piezo Electronic Alarm Buzzer Key Features and Benefits: quality construction: Made from durable ABS plastic for longlasting performance. Reliable performance model: HYD4218, designed to operate at DC 915V with a rated current of 12mA. Loud and clear sound: Produces up to 85 dB at a frequency of 4000±500Hz, ensuring alerts are easily heard. Compact and efficient: Small size for spacesaving installation while maintaining low energy usage. Strong alarm capability: voice pressure with up to 90 dB output for attentiongrabbing alerts. Specifications: Model: HYD4218 Voltage: DC 915V Rated Current: 12mA Frequency: 4000±500Hz Sound Output: 85 dB Material: ABS Plastic Applications: Security systems: Ideal for use in alarm panels, motion detectors, or intrusion detection systems to warn of potential threats. Home alarm systems: Provides an audible alert for door and window breach sensors or safety alarms. Industrial and electronic projects: Can be integrated into warning devices or industrial monitors where a clear, reliable sound signal is needed. Performance and Compatibility: Designed for straightforward integration into various electronic circuits. Suitable for both commercial and residential alarm configurations. Low power consumption helps preserve system efficiency without sacrificing sound effectiveness. This set of three active piezo electronic buzzers delivers a strong, consistent alarm signal in a compact, durable package, making it an choice for reliability alert systems.