Radio Shack, Caller Id/call Waiting Id Box
See who's calling without having to ask.The adjustable, backlit display on this compact, 99-number Caller ID* unit swivels for maximum readability on your desktop or wall.Stores up to 99 single Caller ID* numbers or up to 64 names and numbersEasily review your calls using the scroll up/down control1-touch callback allows you to return calls at the touch of a buttonBlue backlight for easy nighttime viewingYou'll also need4 "AA" batteriesPhone serviceCaller ID (through phone company)Tech SpecsDimensions  Product Weight   16 ounces     General Features  Model   43-3903     Product Type   Caller ID     Body Material   Multi     Miscellaneous Features  Supported Languages   English     Inputs   1 x RJ11(Phone jack)     Outputs   1 x RJ11(Phone jack)     Power Features  Power Device   AA batteries (4)     Battery Features  Battery Type   Product     Chemistry   Alkaline     Size   AA     Voltage   1.5 Volts