description Weber control knobs with 1 3/8" stem. Features Dimensions: 2 1/4" diameter DD-shaped 1 3/8" valve stem opening. Made of plastic. Fits Spirit 3-burner series grills manufactured in 2007. brand-weber,brand-weber-model-3730001,brand-weber-model-3731001,brand-weber-model-3820301,brand-weber-model-3821001,brand-weber-model-3830001,brand-weber-model-3831001