The ARX-910-TB Termination Board is a small (2.5"x1.5"x.57") adapter that provides a mechanical termination for the DC power and audio wiring for the ARX-910 (also compatible with the ARX-900). The ARX-910-TB also provides a pass-through so that the ARX-USBEXT USB Extender can be connected to the ARX-910 radio at the same time. On one side the ARX-910-TB connects to the ARX-910 radio via a CAT5 cable, and on the other side (optionally) connects to the ARX-USBEXT.