Used Panasonic Central Unit, model 824, like new, very clean. 16 internal lines, 6 external lines. Price: 350 SAR Used Panasonic Central Unit, model 824, like new, very clean. 8 internal lines, 3 external lines. Price: 200 SAR Used Panasonic Central Unit, model 308, with an expansion switch. 6 internal lines. Price: 150 SAR. The central unit comes with the switch.