Adjustable detection distance: 10 cm to 100 cm. Turning the control clockwise increases the detection range, while turning it counterclockwise makes it shorter. The knob cannot rotate 360 degrees. Sensor principle: Non-contact infrared sensor with an MCU circuit of Taiwanese production, using the diffuse reflection of infrared light on objects. When a person or object enters the defined detection area, the sensor outputs a signal. When it leaves the area, the output is turned off. Key benefits: Provides hands-free presence detection for automatic control. The adjustable range allows use in different spaces. Non-contact operation supports hygienic and safe interaction. Output is active only when presence is detected, enabling straightforward integration with downstream devices. Use scenarios: - Automatic doors or gates: presence triggers opening and then closes when the user passes. - Hands-free lighting or display activation in hallways, restrooms, or kiosks. - Presence-based signaling for energy management or security systems, triggering actions when someone enters the area.