After I excluded myself several times with my old auxiliary lock successfully, I needed a new one. Thanks to Amazon for the quick delivery !! Unwrapped, studying instructions. Class, the lock can be mounted on the right and on the left side of the door. That I had not thought of that one also has to note something. The change in direction was the smallest problem. Thus, the cylinder and the lock fits into the door I had to drill first. The cylinder is in fact not as round as the castle of my predecessor, but has still above a circular tower, where a screw comes in. Super for safety! Bad for the time you have to plan when installing more.
Otherwise, I can only say that it is well made, necessary screws and adapters, spacers are included.