This is not on the manufacturer at all, they stated the inside bore diameter of this door knob, but it was the one thing I didn’t check on my door knobs before ordering. All our door knobs were from the ‘80s and back then standard bore diameter was less than 2”. Most knobs today are 2-18” ish so like me you may need to buy a kit to bore out your doorknob hole to fit these. Aside from that they have good spring action in turning and closing. I read lots of negative reviews saying they scratch easy, haven’t seen that yet and they didn’t scratch getting installed so…