"We've been working on some help articles to assist our customers or anyone else with some basics about door hardware. You can check these out in the help section of our website including a new Purchasing Guide that walks you through the basics of purchasing door hardware so that you are educated before buying and as a result, order the correct thing for your application the first time. You can view these help articles in the help section of our website here: http://www.directdoorhardware.com/Help/Doorknobhelp_index.htm"