Panasonic KX-TA82483 Digital Expansion Card for Business Phone System - Compatible with KX-TA824 PBX - Add 3 External Lines & 8 Extensions - Ideal for Office, Call Center & Small Business Communication

It worked, as expected. Caveat: The eleven jack numbers here are, understandably, fixed in their logical assignments (J09-J19?) (to my knowledge these "extension numbers" are not changeable; although there is a thick book pertinent to "programming" the system. And I certainly favor the default assignments, anyway! There is another extension card that has jacks at J20-etc and I don't know how to buy that.E.G.: If you're at one phone and want to page someone whose phone line is connected to Jack09, you punch 109* to make that phone ring. When the recipient answers, you have an intercom connection.