Proflow's aluminium V-belt pulleys are precision CNC-machined to run perfectly true. Machined from 6061-T6 aluminium for extra strength and wear, they feature polished or black powder coated finish. Choose from 1 or 2-groove water pump pulleys for your application. They are available in performance Standard or ratios for increased horsepower during normal street driving, and high water flow ratios for increased cooling during critical low-speed driving, to prevent overheating.