Ding Dong: yes, not lower 90DB The battery is equipped with a rechargeable lithium battery (2000mAh) The keys:3 multifunctional buttons Maximum storage capacity of 128GB (TF card format is FAT32)<br><br>Host size (indoor) 125x78x20mm,sub unit sizes (outdoor) 60x60x13mm Adjustable ringtone:built-in multiple ringtone Charging interface:TYPE-C USB night vision:940nm infrared light/3 lights Standby power consumption 30uA, Maximum power consumption 300mA (infrared light, screen on) Output format JPG/avi Suitable door thickness:40mm-110mm, suitable aperture:16mm-45mm Automatic capture and recording:support Infrared night vision function:support Low battery alarm:supports Adjustable volume:support (0-100) The doorbell function supports a field of view angle of 77 degrees Motion Detection (PIR) support (automatic screen on upon arrival) Colour:As Shown Material:ABS<br><br>Package Contents: 1 * Door Bell Kit<br><br>Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.