Edelbrock Competition 3.250in. pulley part #15850 allows you to fine tune the air flow and performance of your C7 Corvette or Enforcer Supercharger system to your preference. The Edelbrock #15850 features a 10-rib design for use with our street rod and muscle car Supercharger systems. Edelbrock Competition pulley part #15850 offers a Black Anodized finish 3.25in. 10-Rib Edelbrock S/C Pulley in Black Finish for Enforcer Systems