The CB305 is a cable designed to function as a connector between the AVDI interface and most modern Harley-Davidson bikes. The cable supports motorcycles using K-Line (using the 4-pin connector) and CAN-BUS (using the 6-pin connector). The need for this connection exists because most modern motorcycle manufacturers still use a "make specific" diagnostic connector rather than OBD.
*Note: Older Harley-Davidson bikes that use a 4-PIN connector may need to communicate through the SAE J1850 protocols. In such cases a J1850 adapter will be required.