Just so you have a little more understanding of the MRT transponder:
The cloning of a transponder is done by MRT, which would be transponder number 1. Besides that number, there are 9 or 10 other numbers stored in the transponder. All these numbers normally come on a piece of paper that comes with the MRT transponder. You can change the transponder number by using the button on the transponder. I have never had the need to change the transponder number though....