This is a radio antenna conversion cable that was used in Nissan cars from quite a while ago. It's a male/female type, so it can be used when connecting an FM modulator-type audio device. If the female side is not used, it's also possible to install a Nissan genuine diversity-compatible audio system in a vehicle that doesn't have diversity on the vehicle side. I don't know the detailed compatibility. Discounts are not available except for bulk purchases.