THIS^^^^^ I would deff read on this before getting too deep into something that you may have an issue with to see if you are even willing to take on the task. Id recommend that you have someone with experience to install it
If you are not familiar with the equipment it can deff get you into some trouble. I think its best he take it to a respected Audio shop and have it installed correctly and try to get some type of install warranty on it. Spend a few bucks and get it done IMHO.
Remote in is pretty self-explanatory. It's the remote signal from your headunit.
Key mem I'm not sure
Optical select needs 12v power if you are using the optical input.
Aux sel needs 12v power is you are using aux input
Mem A and mem B are for selecting either of the saved tunes in the unit. Also 12v power if I'm not mistaken.
Remote in is pretty self-explanatory. It's the remote signal from your headunit.
Key mem I'm not sure
Optical select needs 12v power if you are using the optical input.
Aux sel needs 12v power is you are using aux input
Mem A and mem B are for selecting either of the saved tunes in the unit. Also 12v power if I'm not mistaken.