This key will work on most Yale locks found on residential and commercial door-knobs, dead-bolts, and mortise cylinders. This key is cut on a Y1 / 999 blank. It will also work on locks using a Y2 blank.
This key is designed so that once inserted into the lock it can never be removed again. As a result, anyone with a previously working key will not be able to use it to open the lock. The lock will only be able to be unlocked from the inside once this key has been inserted.