Edelbrock 2.75in. part #15871 pulley allow you to fine tune the airflow and performance of your Edelbrock Supercharger System to your preference. Edelbrock pulley is a 8-rib design for use with any of our Professional Tuner systems. Edelbrock pulley feature a black anodized finish.- 2.75in. 8-Rib Edelbrock's/C Pulley in Black Finish for - Pro Tuner System