1. This design uses the American standard UL lock, double lock, and opened at the same time, before the main key is not inserted, guest keys cannot be inserted, so as to ensure the safe: the door open when guest key can not be pulled out, in order to prevent the loss of key.
2. Between the lock and key for a distance of 47 mm, can prevent the rotation of a key when the finger is another key to scratch it, the general lock because of small volume, the distance between the two keys to about 33 mm.