This is a hard review to write, because I really do like the door knob and the product itself deserves 5 stars. However, it arrives with almost no installation instructions - a wire runs through the middle of the door knob; where does it attach? Some careful looking and I figured it out. Reviews that said there was an installation video, I would ask, “Where?” I couldn't find it for this exact door knob, and the manufacturer doesn't tell you on the basic guide to installing. They include a very helpful booklet on programming the door knob, and I didn't have difficulty with that. So, except for taking a while to figure out the installation, it was very good and I would buy it again.