The Solo PRO unit is delivered with two USB cables used to connect up to two external modems to the unit.
The cables connect to the USB ports on the left and right panels of the unit. The cables are marked with L/A (left) and R/A (right) to indicate on which side of the unit to connect them.
The modem connected to the left panel of the unit is identified as 1. The modem connected to the right panel of the unit is identified as 2.
It is recommended to bind the modems into the elastic fasteners on the protective sleeve to keep them from moving around and potentially disconnecting from the unit during your live session.