Two part Special Lock out Key Blank that uses the Schlage C keyway.
How It works: Stick the bottom part " A " into a lock, and pull back. The key gets trapped. Stick the top part " B " into the lock, pull both A and B out at the same time.
Use this key to lock out any key from working the lock. Often used by landlords to restrict access to keep unpaid tenants out of a apartment or room until they pay their rent. Also can be used to temporally close all access to a lock / door in the case of theft.