Flamesources dot com conversion kit. Factory instructions are included. These brass orifices are a replacement for grilles that use male threaded orifices. Unless otherwise specified, they will be custom bored for use with natural gas rated at 7" WC for this application only. Please contact seller if you're planning to install a fuel regulator in line with your grille. Many bar-b-ques use these types of orifices, and they might retrofit a number of other brands. These are made for that specific Weber model with front control knobs (not side knobs) made after 2010.