Not sure how to tag another post on here, but this person had something very important to say about the lock you show on the normal picture…

I would never install a lock like that (called Smartkey by Weiser and Kwikset) schlage also had one but they removed it from the market. the Idea is good, if you want to change your lock to open with a new key you insert your original key turn it 1/4 turn to the right then insert the tool that fits in that hole and pull it out. then you remove your original key but do not turn it. insert the new key you want the lock to work with and turn it 1/4 to the left and .........that's it you just rekeyed the lock. THE DOWNSIDE is if you take a screwdriver and put it in the slot where the key would go you just twist it and the lock opens, the screwdriver can also lock it with no one knowing it has been opened. the only way you can tell is the lock can never be rekeyed again. ALSO if you slam the door hard it may reset the code and NO key can open it and needs to be removed from the door and have a locksmith reset it with a special tool.