1Adopting premium motor, all the buzzer alarms have high sensitivity for quick trigger. 280 dB loud and intermittent sound ensures that you will immediately detect the alarm. 3Adopting durable ABS material, the buzzer will not easily corrode in varied environments. 4This set ncludes 5 active buzz alarms to satisfy your various working needs, very practical. 5With small size, light weight and 2 connecting wires, the installation is very convenient.5 x Black Buzzer AlarmItem Type: Buzzer AlarmMaterial: ABS MaterialModel: SFM-27IIRated Voltage: 12VWorking Voltage: DC 3-24VDrive Mode: PiezoelectricWhether Active Head: ActiveFunction: Signal Alarm