The Zenith EZ hang up device allows you to get rid of annoying telemarketer calls quickly and easily without even having to speak with them. With the easy setup you will be ready to disconnect telemarketer calls in seconds. With just a push of a button a short and polite yet firm message is played and then the call is disconnected. The telemarketer will hear: "I am sorry; this number does not accept this type of call. Please regard this message as your notification to remove this number from your list. Thank You". The unit measures 2 inches long by 1 inch high. Please note that this item does not work with Digital phone systems or multi-line PBX systems.