【Hidden Password & Mistake Prevention】The password is located at the bottom of the lock and is hidden. To change the password, you need to unscrew the screw and push the setting key up until the "SET" key appears, and then reset the password. This can effectively avoid the problem of failing to open the password due to unintentional password change. 【High Security Performance】One-piece alloy lock body, 304 stainless steel lock hook, 8mm anti-theft shackle, can not be removed or broken manually, and can effectively prevent cutting and searching. The 4-digit password metal wheel has 10,000 password combinations, which can achieve a high level of anti-theft. 【One-key unlock function】The original password of the lock is 0-0-0-0. After setting the password, press the middle button to open the lock, which is very convenient to use. Note: Take a photo to record the new password when you change the password, so as to avoid failing to open it. 【Unique appearance design】The square shell design