USB programming cable. This cable uses a 3.5mm jack to connect to the radio's speaker-microphone port.

Internal VOX (Voice Operated Transmit) gain and delay times are adjustable through the software for hands-free use with compatible headsets. Programming Step-by-Step IC-F3003 IC-F4003 | Products | Icom Inc.

requires a specific software-hardware combination to communicate with the radio's internal EEPROM.