Applicable door thickness: standard 30 ~ 45mm (non-standard 45 ~ 58mm, 58 ~ 70mm). The key can be used to unlock the lock. There is a European standard engraved pattern key hole baffle. Even without knowing the memory number, you can go in and out at any time with the key. (single barrel or double barrel). 12 buttons can be used to combine memory numbers, and more than 4000 memory numbers can be selected. You can code at will, and any memory number can be in any order. Universal key: a key can be used in multiple locks. After the user selects the channel lock, both indoor and outdoor sides can pass freely without password.