Flav-R-Wave™ is just another word for heat plate, heat diffuser, flavour bar... The list goes on and on. What we're saying, is that each barbecue company has their own name for these special little parts. There's no right or wrong name, we'll know what you're talking about.
These Broil King Flav-R-Wave™ pieces are essential to protecting the burner in your barbecue from any sort of grease or other barbecue drippings falling onto your burner. When you get grease dripping on your burner, you run the risk of it burning a whole right through it. No one needs that.
Keep your eyes on this part. It's pretty easy to tell when it needs replacing. As soon as you've got spots that have burned through, it's time to stop by and grab a new one.