Indicating Lock / lock

When we lock the door,we may feel confused whether the door is completely locked.And at times we may also experience the wonder that whether we turn the lock the correct way with the proper direction.However, this lock could provide us a good hint.
When the key is rotated,the dial rotated together.There are two sets of arrows under the dial,respectively indicate the direction of the locking and unlocking through the hole of the dial.
When the fluorescent blue stripes is connected seamlessly，it indicates that the lock is locked.To the contrary，if the stripes is disconnected,it shows that the lock is unlocked.