Love these handles BUT my carpenter tells me they are a pain in the neck to install.  The major flaw is that the rectangular plate is about 1/8” too narrow for doors that have the door knob hole pre-drilled. This is important if you are replacing existing knobs with these ones. You can see a sliver of the pre-drilled hole when the knob is installed. He found a workaround but it now means each doorknob takes over an hour to install and that time = money!!