you will get a non transmitting key with your tumblers and you have to order by vin #. it costs about $225 for the parts alone and you have to go through chrysler. It did not solve my sticky key problem. I had to replace the steering lock and that solved the problem. If you order the lock for a 03 or 04 170 slk from Mercedes, it will be about $100 cheaper than ordering a xfire part from chysler. That part was $160. There is a special tool for removing the lock tumblers and the smaller key that comes with the tumblers must be used in conjunction. don't use anything else.