European standard fixed spring lock and cylindrical lock, it is very simple to change the memory number. Mechanical code lock features: regardless of the length of the lock rod, it is suitable for door frames with centers of 70-72mm, 85mm and 92mm. 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). The excellent durability mechanical device has passed more than 400000 comprehensive power tests. 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 entered in any order. The slippage device can disable the attack and destruction from the outside. The specially processed stainless steel button will not leave any traces. Emergency type: no matter whether it is locked or not, you can go out freely from the room without entering the memory number. Universal key: a key can be used in multiple locks. Free passage function: after the user selects the channel lock, both indoor and outdoor sides can pass freely without password.