This adapter harness works with all of our BenchForce™ PowerBlock switch assemblies. It is meant to be used with scan, tune, and diagnostic tools that have a J1939 connection. Plug the OBD-II end into the PowerBlock, then use your own tool with the other side. This solution is popular among diesel tuners when they are working with 2017-newer Cummins applications. Be sure to check out our growing list of diesel programming harnesses.