Introduction - If you have any usage issues, please Google them yourself
2 with four buttons and a digital control into a simple lock. Four buttons representing the numbers 0, 1, 2, 3, and the password is set to 3, boot digital display " -" wait for password entry when you enter the correct character " 3" 2 seconds, opened the door, enter the error , show " F" 2 seconds required to complete the following topics.