This Y-cable is for vehicles (such as some Freightliner Cascadias and others) that have the diagnostic port adjacent to the clutch pedal or in some other inconvenient location. This cable allows the diagnostic port to be split, with one port going to the original location and the other going to the Zed Connect Bluetooth Data Link Adapter. Note: This cable is compatible with both Type 1 (black or gray) and Type 2 (green) 9-pin connectors. Order this cable if the 9-pin connector in your vehicle is NOT green or if you don't know which color it is. Type 1 Threaded Flange Male to Type 2 Female to Type 1 Square Flange Male.