This product is designed for easy audio installation in 24V trucks and dump trucks by connecting a DC-DC converter (commonly known as a "deco-deco") and a 14-pin harness for trucks. Simply remove the original radio or CD deck, connect the rear connector, and connect the wires of the same color from your 12V car audio (deck). There is no risk of incorrect wiring, so you can rest assured. If you have experience installing car audio in passenger cars, you should be able to install it easily. Compatible with 24V vehicles from Hino, Isuzu, Mitsubishi Fuso, and UD manufactured after 2001. *Note: Not compatible with the new 17 Super Great. *Note: Not compatible with trucks that have Bluetooth installed as standard equipment, as the connector shape is different. Although common to all four Japanese car manufacturers, the connector shape may differ in some vehicles, so please check the connector shape before purchasing. Operation is the same as in passenger cars: it operates with the key ACC and turns off with the key OFF. (Backup power is supported, and the clock and memory function normally, just like in passenger cars.) *There is no illumination function. -------------------------------------------------------- ・All parts used are new. ・The deco-deco is tested to ensure it outputs around 12V using a tester. ・We have tested the operation by connecting a 24V power supply, speakers, and a deck to simulate installation in a vehicle. *Please be sure to check the connector shape before purchasing. All parts and wiring used are from reliable domestic manufacturers. The deco-deco unit itself is imported from overseas and purchased from a domestic distributor, but please note that there may be some minor scratches on the surface even though it is new. Installation is at your own risk. We are not responsible for any damage, malfunction, smoke, or fire that may occur during installation. --------------------------------------------------------