I was wanting to upgrade my head unit, the current head unit use the clarion wired remotes M101RC at the helm and transom, Does anyone know which head units are these compatible with? I really don't what to have to replace both of these remotes if possible, any help is appreciated.

I don't think it will work with any of the newer head units.

If you go to Clarion's web site and look at the model you wanting to upgrade to, it will tell you what remotes will work on that head unit. I have been looking into this as well. I think you might be able to use the exsiting extention cable that is there you would just have to buy the remotes.