If you have a six burner Weber gas grill then you are playing with a Summit.
If your Weber Summit has eleven individual Flavorizer bars then here is what you need.
The heavy gauge stainless steel is the same price as the regular stainless and will last longer.
If your Weber Summit has two Flavorizer bar assemblies then check to see if you have a built in smoker box.
There are no aftermarket heavy gauge stainless Flavorizer bars for the assemblies.
The Weber Summit line of grills gets real confusing after 2007.
There is an aftermarket manufacturer who sells individual heavy duty Flavorizer bars which fits the Weber Summit E-650, E-670, S-420, S-440, S-450, S-460, S-470, S-620, S-640, S-650, S-660. Click here to buy them.
It looks like they are selling them one at a time and not as the complete set.
An alternative is to call Weber customer service at (1-800-446-1071) for the correct replacements. Weber does not sell the replacements through Amazon; you have to call them.