Product Description Material: Aluminum Features: 1. Single Groove. 2. 6.60" Diameter. Applicable Models: Suits Chevy Big Block 396 454 1965-1968 Engine. Applicable Water Pump: Suits Short Water Pump. Package Included Including all items in the picture. Professional Installation is Highly Recommended (No Instruction Included). We have multiple warehouses from which your package will be shipped.