Universal Car Antenna Harness Adapter for Toyota 4Runner - Dual Plug Radio Installation Kit - Perfect for Aftermarket Stereo & Audio System Upgrades

I used this with a Android-based head unit by Atoto, installed in my 2007 4Runner. You plug the (2) smaller and larger antenna leads from the 4Runner into this adapter, then plug the single plug of the adapter into the back of your new head unit. (I also followed the wiring/installation instructions carefully from Atoto...I am not sure but it may provide power to an antenna booster or power unit built into the 4Runner, allowing this antenna adapter to work correctly. Not sure about this but it works. There's much confusion online about exactly how the "diversity antenna" from Toyota functions.) Reception is identical to what I was getting previously with the factory head unit, nice and clear. I do not get AM stations very well either way (factory unit previously installed or with the new head unit with this adapter), this may simply be due to distance/signal strength and I don't really care about AM anyway, but FM is clear on multiple stations even some at a distance.