The infrared doorbell has an effective sensing distance of 4 meters and will play a preloaded sound when someone enters the detection range. o files can be customized by connecting the device to a computer via USB cable and copying new MP3 format o files to the player. The MP3 files will play automatically when the PIR sensor is activated. Note: The device may not be recognized on Windows 8/10 systems. Ideal for retail environments, this doorbell emits a welcoming message, greeting prompt, warning alert, or voice advertisement upon detecting human movement. Different o files can be uploaded based on specific application needs to achieve optimal results. Power options include 3 AAA batteries (not included) or connection via the Mini USB port for external power supply. Note: o replacement is not supported through the Mini USB port. Features an anti-theft function: when leaving the store, switch to alarm mode to detect and alert against unauthorized approach, helping deter potential intruders. Equipped with memory functionality—selected o and volume settings are retained even after the device powers off or enters sleep mode. Specifications: Model: Microsound V22.12 Product Type: MP3 Infrared Doorbell o Format: MP3 (Bit Rate: 8–320Kbps), with two volume levels: low or maximum Built-in Speaker: 8 ohm 1W speaker Sensor: Infrared induction with automatic detection Power Supply: DC 3V–5V stabilized voltage Working Current: 100uA (Sleep Mode); 130mA (at DC 4.7V, Playback Mode) Infrared Detection Distance: 4 meters (45° angle) Sample Rate: 14KHz Memory: Built-in 4Mbit SPI FLASH Installation: Ceiling or wall mount Power Source: External USB power (DC 5V) or 3 AAA batteries (not included) Working Current: 100uA (Standby); 60mA (Playback) Operating Humidity: 10–85% RH Color: White Material: ABS Dimensions: 90 x 60 x 26.6 mm Package Includes: 1 x o Doorbell Note: Lighting and display differences may cause slight color variations between the image and the actual item. Measurement tolerances are +/- 1–3 cm.