Evening all, hope your all keeping well.

Please can someone advise what ISO connection I need.

The right is out of the existing Alpine head unit, the left is what I have been provided with new.

Many Thanks

Is the Alpine unit an original factory fitted item or an aftermarket unit?

Original

I fitted an aftermarket Alpine head unit to replace the original (not alpine) Land Rover head unit. The original unit had two plugs on the main harness into the original unit. The Alpine unit has a single plug into the unit. So an adaptor harness is needed, to take the two main harness plugs onto a single plug to go into the unit. Mine looked similar to your pictured harness on the left. If your Alpine unit was factory fitted, I would guess the main harness was already tailored to fit straight onto the unit without an adaptor.