The Edelbrock pulley part #15824 allow you to fine tune the airflow and performance of your Edelbrock Supercharger System to your preference. Edelbrock pulley part #15824 is for use with any of our Professional Tuner systems. This pulley features a black anodized finish. 3.875in. 6-Rib Edelbrock's/C Pulley in Black Finish for Pro Tuner System.