1: What should I do if the smart lock is suddenly broken? 

do not worry! The paper installation guide you receive will explain how to use a special tool to unlock the fingerprint lock if it is damaged. (Note: this method should only be used in an emergency!) 
2:Smart locks are divided into password & fingerprint version smart locks and Tuya APP & password smart locks.
(Both smart locks are the same size.)
Password & fingerprint smart lock cylinder can store 50 fingerprints and 50 passwords.

3: fingerprint smart locks 
Password & fingerprint smart lock cylinder can store 50 fingerprints and 50 passwords.

Tuya APP
(Go to the webpage or app store to download Tuya,
and open all permissions of Tuya APP after the download is complete)
If you need an electronic version manual (which can be translated into the text you need), please contact the seller and leave your email.
The paper manual is in English.
Special reminder: The smart lock can only connect to one mobile phone Bluetooth at the same time. If you need to use another mobile phone, please turn off the Bluetooth of the first mobile phone connected to the smart lock or wait 3 minutes for the smart lock to automatically sleep, then wake up the smart lock and connect to other mobile phones.

lock cylinder size
The size of this  lock can be adjusted freely.
Can replace almost all sizes of lock cylinders.
Can replace the lock cylinder with a total length of 6CM to 16CM.
The total length of the lock cylinder = the indoor end of the lock cylinder + the outdoor end of the lock cylinder.
The inner end size of the lock cylinder is suitable for 3CM to 9CM.
The outer end size of the lock cylinder is suitable for 3CM to 6.5CM.

Type-c emergency power supply interface

Can be used for emergency power supply when the battery is dead

Low battery automatic alarm sound

When the battery power is lower than 5%, the Smart lock will automatically sound an alarm

Available in two colors: black and silver