Empi 8688 Black Bolt On Sand Seal Stock Size Aluminum Degree Crankshaft Pulley With Holes For Air-cooled Vw Engines. Polished Finish With Sharp Screened Black Timing Marks & Numbers. This Pulley Offers Better Timing Light Accuracy When Tuning Vw Engines. ( Outer Diameter 6-3/4" ) Note: Must Use With Empi 9188 Extra Long Pulley Bolt Sold Separately