I have a 2020 WRX and bought the iDoing headunit. It included an adapter to maintain the factory microphone but the sound quality always sucked. i wanted to use the microphone included with the aftermarket HU but put it into the factory microphone location. I designed this adapter to fit in the factory location and uses the factory screws. Will likely for 15-21 WRX/STi and like some other Subaru's.