High-quality ABS: The doorbell made of high-quality ABS is durable, environmentally friendly, dustproof and moisture-proof, ensuring stable use of the doorbell. Two playback modes: playback in full loop/single loop playback. Press button A to play previous audio and button B to play next audio. It only supports playing MP3 audio files, has two adjustable volume levels, easy to operate and easy to use. Far and strong signals: The maximum detection distance is 4 meters and the signal can penetrate the obstacle. For most families this is quite a long time. Whether you're cooking in the kitchen or weeding in the garden, this doorbell will keep you informed and your visitors will never miss. SD Card Support: With SD card slot, supports Support external SD card. You can copy audio files from SD card to Flash. Download audio files from your computer via USB interface using an SD card (only supports MP3 audio) Usage range: high- Built-in 81W speaker, built-in 32Mbit (4MB) flash memory, widely used places, including supermarkets, offices, shops, hotels, factories and homes. Features: Name Product DescriptionMicro Sound Voice Prompt Material: ABS Induction MethodInfrared Human Body Detection Detection RangeDetection Distance 3 meters, fan surface 120 Power supply mode3 AA batteries or DC5V power supply Power supply: USB / 3*AAA batteries (excluded) Audio: only supports MP3 Volume: two levels Detection distance: maximum 4m White color Package List: 1 * Motion Sensor Doorbell 1 * Bracket