I bought the iGrill Meat Probes to go with my new Genesis II 400 grill.  I have owned a few remote thermometers but, this system is far superior because you can have up to 4 probes to monitor ambient temp at the grill and up to 3 more probes for the various items cooking across the grates. 

The only thing I would change would be to have a little stronger magnets in the cable keepers to better hold the kit together when in storage.