This is a Replacement Idle Mixture Screw for the Traxxas TRX-12 Carb. FEATURES: Pre-installed gasket INCLUDES: One Needle REQUIRES: Carb. SPECS: Length: 19.1 mm (0.75") Diameter: 3.2 mm (0.125") COMMENTS: None jmm 12/16/01 ir/kh BOX DIMENSIONS: 3.13" W. X .25" H. X 3.63" L. BOX WEIGHT: .01 LBS.