The good: This is a replacemente shell for the original key. We have a 2013 CMax Energi Plugin. I was able to disassemble the original key and move the battery, circuit and contacts to the new shell and it worked perfectly. No need for reprogram or expensive trip to the dealer.The not so good: the quality is not as the original as it feels lighter and the button feel less durable but for the price i cannot complain.The process:I am an Engineer but as long as you are fairly comfortable with opening and closing gadgets, then you should be able to do it without any problem.In my case, my key spent too much time on my bag and the button have been pressed to hard to the point that the key will randomly press the button and unlock the car or bring the windows down. I opened the original key. Commercial series cps r05 090 2.