Each personal transponder from AMB has a unique number, this then gets associated to your name. The handouts have a number but it is unually between 1 and 10. The other option is to buy a transponder from MRT. they can either offer them with 10 numbers, 20 numbers or a copy of your AMB transponder number. The 10 and 20 number options may be limited at a big event since they are not unique number, but the same for everyone who buys a 10 or 20 number transponder.

Personally I got a AMB one to get a personally number, then had a few copies made by MRT. MRT was about $60 each, so a lot less than the originall AMB. That way all my cars have the same TX number.

John