Includes spring loaded needles and .0935 seats. Manufactured by Weber USA?, Performer Series square-bore carbs are all-aluminum, ball-burnished and lightweight. There are no powervalves to blow or plastic parts to break and no gaskets below the fuel level which means no leaks. The two-piece construction resistswarping. Metering rods can be changed within seconds without carburetor removal. Each carburetor is flow tested to ensure quick, easy installation. Includes exclusive 36 page Owners Manual (except part #1400). Tuning required.