Belsee two / Four Channel High Level to Low Level Frequency Signal Converter Adapter Speaker Wire to RCA
Usually our special head unit can be compatible with the original car sound system like the Bose amplifier. But some cars have low Level Frequency Signal , so need this adapter.
Usually need 4 channel High Level to Low Level Frequency Signal Converter for aftermarket head unit car radio. It is according to your factory power plug of radio.
More information read this link:
https://www.belsee.com/blogs/technical/852757.html
This is four channel high frequency to low frequency signal adapter:
This is two channel high frequency to low frequency signal adapter: