Had to replace a door knob that's been on the door for 60 years. This knob was the first I've ever installed. The instructions were minimal on the insert page, but iThe pictures were very helpful. No problems whatsoever except for one. It is a round door knob. I have a battery operated screwdriver, which would not fit straight into The screws that secure the door knob. And the screwdriver also did not have the right angle.  I was very careful, but it almost stripped the screws. Even for the screwdriver it was an odd angle. But I had success  and the door knob works great!  There is a question mark shaped wire that was included,  no information about what it is!