Weber #70377 Set of 2 Replacement Control Knobs for Summit Grills Weber part # 70377 Set of 2 replacement knobs for Weber Summit gas grills, model years 2007 thru 2010. Knobs measure approximately 2-1/2" in diameter. Stem has a "D" Hole insert. Please visit Weber's website to ensure you order the correct parts for your specific grill. It is best to look up by serial #. The following link will also help you find the alpha numeric number. http://help.weber.com/schematics/#serial-number