Accordion Shutter HV Lock - Key & Thumbturn
Sold separately as Inside and Outside. The Inside facing mechanism is the Thumbturn and the Outside facing mechanism is the Keyhole portion of the lock.
These are great for a second floor application where you might need to secure your accordion shutters from the inside of your home. These locks have a keyhole on the exterior face and a thumbturn on the interior.
These locks are also a must for fire safety reasons. With traditional locks, there is no way to unlock your shutters from the inside. This feature alone should be a reason to have these installed on your bedroom windows.