This transfer case shift module is an OEM part for Dodge Ram 2500 4WD trucks with a 5.9 Cummins engine, made by Mopar. The part number is P56028589AD and the OE/OEM part number is 589AD. It is designed for use in the interior of the vehicle and can be used to control the transfer case shifting. This module is compatible with a variety of Ram truck models, including those manufactured in 2004 and 2005.