uxcell Infrared IR Detect Welcome Alarm Intelligent Greeting Doorbell Green Product Name: Welcome Doorbell; Color: Green; Material: Plastic Size: 8.3 x 4 x 8.5cm/3.3" x 1.6" x 3.3"(L*W*H); Net Weight: 112g; Package Content: 1 x Welcome Doorbell,Several Installation Parts Detecting Range: &lt;8M; Measuring Angle: 60 Degree, Fan Angle of 110 Degree; Memory Music: 32 Power Supply Mode: DC 7.5V, or 3 x AAA Battery; Boot Delay: 10 Seconds Sound Pressure: 95db+/-5db; Induction Way: Infrared Sensor Triggered