The infrared doorbell has an effective sensing distance of 4 meters and will play a preloaded sound when someone enters the detection range. Audio files can be customized by connecting the device to a computer via USB cable and copying new MP3 format audio files to the player. The device will automatically play the audio when the PIR sensor is activated. Note: The device may be recognized on Windows 7/XP computers but not on Windows 8/10.Ideal for retail environments, this doorbell emits a warm welcome, greeting prompt, warning alert, or voice message when human motion is detected. Different audio files can be loaded depending on the application to achieve the desired effect.Power options include 3 AAA batteries (not included) or external power via the Mini USB port. Note: Audio replacement is not supported through the Mini USB port.Features a practical anti-theft function. When leaving the store, switch to alarm mode to detect and alert approaching individuals, helping to deter potential intruders.Designed with memory functionality. Once audio selection and volume adjustment are set, the device retains these settings even after entering sleep mode or power cycling.Specifications: Model: Microsound V22.12 Product Type: MP3 Infrared Doorbell Audio Format: MP3 (Bit Rate: 8320 Kbps), with two volume levels: low or maximum Built-in Speaker: 8 ohm 1W Sensor: Infrared induction, supports automatic detection Power Supply: DC 3V5V stabilized voltage Working Current: 100 A (Sleep Standby Mode); 130 mA (at DC 4.7V, Playing Mode) Infrared Detection Distance: 4 meters (45 angle) Sample Rate: 14 KHz Memory: Built-in 4 Mbit SPI FLASH Installation: Ceiling or wall mount Power Source: External USB 5V power or 3 AAA batteries (not included) Working Current: 100 A (Sleep); 60 mA (Playback) Humidity Range: 1085% RH Color: White Material: ABS Dimensions: 90 x 60 x 26.6 mm Package Includes: 1 x Audio Doorbell Note: Light and display differences may cause slight color variations between the image and the actual item. Measurement may vary by 13 cm.