master keying

• 

  Master Keying (I). The four main types of master keying

  07/02/2018

  Perhaps you’ve seen someone you know open the door to their house with the same key they use to open their lobby door. Is it magic? Absolutely not. Neither is it just a way to make things easier for themselves but also one that compromises their lock security. Far from it. You have simply witnessed [...]

  Read more