The Caller ID device is designed to store and display information provided by your local telephone company to subscribers of Call Information Service. The Information can include the name, telephone number, message waiting, date and time of each call. When used with this service, the Caller ID unit allows you to screen calls by displaying the name and telephone number of each caller before you answer the phone. In addition, the unit stores information about the calls you received whether or not the calls are answered for later reference.