This is the Bosch Power Line Carrier (PLC) adapter for the Bosch ESI Truck tool. You can't always connect to a trailer ABS through the truck, so you would need this cable to connect directly to the trailer. You would either use this cable "in-line" with your 7-way plug from the truck or else purchase the extra cable kit to connect to a battery.

• J2497 Power line Carrier (PLC) communication compatible
• Allows direct connection to trailer
• Works with tractor present or without the tractor present (external power supply is necessary without tractor)
• Bosch ESI[Truck] trailer ABS coverage for Bendix, Haldex, Meritor Wabco, and Wabash systems