Specification: Features:Human body induction, induction distance up to 4 meters.Built-in 8Ω1W 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 NewMaterial: ABSColor: WhitePower Supply: USB/3 x AAA batteries (excluded)Audio: Only support MP3Volume: Two levelsDetection Distance: Maximum 4mSpeaker: Built-in 8Ω 1W speakerMemory: Built-in 32Mbit4Mbyteflash memoryMemory Expansion: Not SupportPackage List:1 x Motion Sensor Doorbell1 x Bracket