I just put this lock on 3 of my offices with aluminum stile doors. It might be costly on the initial buy but after years of spending hundreds per year to have locks re-keyed, it will easily pay for itself. No more having to have a pile of keys to give to employees and try to keep track of who has them and who hasn't turned one in, ect. Also no more worrying about if an employee has copied your store key or not. Now when someone leaves, just pop it off and change the code. You can have as many digits as you would like with additional insets at only a few bucks. I change my code 2-3 times a year now.