Please check the following FAQ for different products:

HDMI to AV converter or AV to HDMI converter, which one is right for me?

For HDMI to AV/RCA Converter:

HDMI to AV/RCA Converter FAQ

RASFOX HDMI TO AV CONVERTER FOR AMAZON FIRE STICK INSTALLATION GUIDE

For AV/RCA to HDMI Converter:

AV/RCA to HDMI Converter FAQ

HDMI SPLITTERS OR HDMI SWITCHES, WHICH ONE IS RIGHT FOR ME?

For HDMI Switch FS501:

HDMI Switch FS501 FAQ