This is a stock diameter pulley.  UR developed this version because the performance benefits of weight reduction outweigh the need for underdrive, especially for audio enthusiasts as some audio competitions require voltage to remain at a specific level. Stock diameter is also important for factory or aftermarket superchargers. Superchargers need the stock diameter to keep the same boost you had with the factory crank pulley. The big weight loss gets you a lot more power to the wheels.

When you want the best pulley sets money can buy don't settle for a cheap time bomb go with

• Alternator Pulley (Stock Diameter)
• Part ID: 011230712
• Regular Price: $104.00
• Product Weight: 0.20lbs
• Shipping Weight: 1.00lbs
• OEM Weight: 0.60lbs