Wireless Infrared Sensor Split Supermarket Welcome Doorbell 1. Material: durable ABS housing 2. Sensors: infrared (detects human presence and issues an alert), Vibration (detects ambient vibration and issues an alert), door sensor (alerts when the main unit's magnetic strip separates, triggered by pushing a door open, particularly suitable for shops with frequently closed glass doors) 3. Main unit requires three AA batteriesUSB 5.0V power adapter; sensor requires three AAA batteriesUSB 5.0V power adapter (batteries not included) 4. Transmitter and receiver frequency: 433MHz (less interference than 315MHz) 5. Receiver battery life: 5-7 months (based on 30 beeps per day) 6. Infrared curtain battery life: 5-7 months (based on 30 detections per day) 7. When customers pass through the detection zone, the receiving unit emits a welcoming tone, creating a friendly shopping environment and alerting store staff. 8. After closing time, the alarm can be used as a burglar alarm with a high-volume speaker, reaching up to 113dB. 9. Custom 8-chord music chip, 40mm large speaker for more pleasant sound, 36 doorbell tones, change at will. 10. Colored light reminder mode is ideal for quiet environments like offices, with adjustable brightness. The night light illuminates the main unit for two minutes after the probe is triggered, making it safer to wake up at night. 11. Horizontal detection angle of 100 degrees, vertical detection angle of 15 degrees, sensing range: 2-8 meters (the range is shorter in higher summer temperatures and varies depending on the installation angle). 12. Long signal transmission distance: the receiver has a built-in wireless loop antenna, with a range of up to 280 meters in open areas. 13. Receiver: 70x40x116mm 14. Infrared curtain: 82x45x74mm 15. Note: this device is intended for indoor use. do not install it in direct sunlight or rain (such as outside tents). to avoid false alarms, avoid areas with high humidity fluctuations and interference, such as air cond