6061-T6 billet aluminum in your choice of outline color Hard-anodized/bright-dipped laser-engraved degree numbers and marks
Prevent loss of cooling when fan cavitates above 4000 RPMs. Threaded for better performance. Smaller than standard size, pulleys are same size as Porsche 912 that slow fan down but don't sacrifice cooling. Increase horsepower up to 10% and are essential for 4500 RPMs and above. Deep "V" groove reduces thrown or twisted belts. 33% lighter than stock. Color outlines pulley.