A multi point locking mechanism this is normally a strip down the edge of the door with a few cases that sit inside.
How to change a lock upvc door.
A few simple steps and tips for changing a upvc door lock in london 1.
A video tutorial on how to replace a full length door lock on a upvc or composite door.
Test the lock by turning the key both right and left a few times and gently tug on the key when it is turned to both.
Only remove the key from the lock once the retaining screw is secured back into place.
All you need to replace your old upvc mechanism with a new central gearbox is a screw driver or drill and a spare 5 minutes.
A cylinder this normally sits inside the door and is accessed with the key from the outside and inside.