The OBDII Pass-Through Splitter allows two products to be simultaneously plugged into the OBDII port such as a Trinity 2 monitor unit, and another product, including, but not limited to, power running boards or other potential OBDII powered products. This new OBDII splitter is fully populated with a 16-pin pass-through, pinned connector. Products may vary as to what can be running at the same time. Not recommended for us with two monitors or tuners plugged in at the same time.