The Edelbrock Replacement Carburetor Needles and Seats help to fine tune or calibrate your carburetor. These are one of the accessories used to maintain your carburetor at its best. They are available in several styles to suit your application needs. This needle is made up of a Viton material and the diameter of the seat size is 0. 0935 inch. The weight is approximately 0. 03 pounds and is not spring loaded. The needles and seats are usually replaced when there is dirt or metal in the needles or if the carburetor floods. It is sold as a pair.