Parts and features
1 - Cylinder and guard
The cylinder contains the lock mechanism. A strong metal shield, the cylinder guard, is fastened to the cylinder collar. Inserting and turning the key actuates the deadbolt. These are ideal when you are installing a handle and lockset on an exterior door.
Some lock manufacturers make systems that can be configured so the user can activate or deactivate the keys that can be used with the lock, without having to call a locksmith.