Have you been in a situation where you wished you changed that lock and made them leave their key? 

And if you have, you'd start to think about - what if the new lock doesn't match? What if that person made a duplicate of the old key? 

Good news is that most modern locks allow locksmiths to simply 'Re-key' them.  This is done by changing the combination of grooves and peaks formed  within the cylinder itself so the old keys won't work.  

No need to change a fully functional and aesthetic lock hardware.  

And even if you had to replace the hardware -  we can re-key the new lock to match your existing keys.*