1. Switch design, save power and worry, long black magnetic back design, storage bracket 2. Large screen display/big sound, easy to read, clear font 3. Weight: about 150g 4. Size: about 2.8x9.5x9.1cm 5. Material: ABS 6. Power supply mode: 1 x AAA battery (need to purchase by yourself) 7. Note: When the bell is ringing, you can press any key to stop the bell; if there is no operation, it will stop automatically for 30 seconds
