to secure the main door lock

[GeKoSc 127]

I will move in soon in a new rented condo. I wonder whether there is an option to secure the main door lock in the apartment witout changig the cylinder of lock?

[Rc2702 4,002]

You got an image of the lock/handle? Round know with lock in middle?

[Rc2702 4,002]

You got an image of the lock/handle? Round knob with lock in middle?

 

If so this works pretty well.

 

Made in Thailand so most hardware stores have these.