Welcome to our store 1Only support to play MP3 audio, two levels of volume are optional. 2Human body induction, induction distance up to 4 meters. 3Built-in 81W speaker, built-in 32Mbit (4Mbyte) flash memory. 4Two playback modes: full loop playback, single loop playback. 5Press the A button to play the previous audio and the B button to play the later audio. Specification Features: Only support to play MP3 audio, two levels of volume are optional. Human body induction, induction distance up to 4 meters. Built-in 81W speaker, built-in 32Mbit (4Mbyte) flash memory. Two playback modes: full loop playback, single loop playback. Press the A button to play the previous audio and the B button to play the later audio. Download audio files from your computer via the USB interface. Power supply mode: three AAA batteries or USB power supply. Specifications: Condition: Brand New Material: ABS Color: White Power Supply: USB/3 x AAA batteries (excluded) Audio: Only support MP3 Volume: Two levels Detection Distance: Maximum 4m Speaker: Built-in 8 1W speaker Memory: Built-in 32Mbit4Mbyteflash memory Memory Expansion: Not Support Package List: 1 x Motion Sensor Doorbell 1 x Bracket 2 x Stickers 100% Satisfaction - Our customers are our top priority. If you find any product problems after receiving the goods, such as damage and incorrect quantity of goods, please contact the seller immediately. We try our best to provide you with satisfactoryaftersalesservic