I have one of those key code box thingies: https://www.amazon.com/Kidde-AccessPoint-001413-Combination-Permanent/dp/B000GTQU22/ref=sr_1_1?s=office-products&ie=UTF8&qid=1470083677&sr=1-1&keywords=key+code+box
No problems so far!
Senior editor at @TheAlcalde magazine in Austin, TX. Ardent Oxford comma supporter. Hoping to eventually visit every state park in Texas (8 down, 87 to go).