I'm guessing any analog system like KX-T 308/616/123211D, KX-TA624/824, KX-TAW-848, KX-TD 308/816/1232, and KX-TDA50 first 4 ports or an analog card in a TDA family of switches.

The backlight may be a problem if you try to run all 8 on a 308, but I'm not sure of that. My 7735 works in all the above boxes.

Carl