I have one of those and they work great. Nice to be able to turn one burner off and cook long term on indirect. Also, in many cases you can turn off both burners and just leave the smoker tray going and keep the temp above that "all important 185 degrees". The manufacturer doesn't "mark" adjustments on the smoker tray. It is assumed you turn the smoker tray to "full on". However, if you take the tray out an peer in there, you can carefully turn it down to lengthen the duration of your smoking chips. This is real nice, very adjustable unit.