Must be used with CAN-Bus Hub, PN 7740 to complete circuit. Without the CAN-Bus Terminator in place at the end of the CAN-Bus system, signals could be distorted. These distorted signals could result in permanent or intermittent problems that include but are not limited to; improper timing, false signals, and repetitious signals. Always be sure to have the MSD Controller and the CAN-Bus Terminator at the ends of the MSD CAN-Bus.