Replace a worn or corroded mixture screw for more accurate idle air metering. This screw is used on Weber 40 DCOE, 45 DCOE, 40 IDF, 44 IDF, and 48 IDF carburetors. Does not fit 32 DCOF, 40 DCO 3, 48 DCO, 50 DCO, or DCN series carburetors. M5x0.9 x 14mm long thread with a 3mm shoulder. Sold individually.