Wacool; Number lock. Secure combination lock. Prevents accidental opening. Childproof. Suitable for all glass terrariums. To set your personal combination. You need to follow the below steps. (1) the lock is preset at factory to open at 000. check the 000 aim at the indication line pass down the button with shape tool . now the lock is ready to open. (2) press down the button with the sharp tool. hold the position until next step has finished. (3)turn the character wheels to set your personal combination. (4)release the button now your private combinatio has set. (5)remember well your new combination. if you want to change it again please repeat.