Reinventing the wheel is something we do not do. However, making the wheel lighter makes it easier to spin. Lightweight crank pulleys have proven horsepower and torque increases time after time. You can get pulleys under driven or same size as stock. We at Agency Power choose to make all of our crank pulleys the same diameter as the factory but reduce the weight. This type of design will not affect alternator power for the enthusiast running extra stereo equipment. This retains the factory belts and fits with no modifications. Our Scion TC pulley is CNC machined 6061 aluminum. Properly broached and includes the timing mark for a balanced OEM quality fit. The pulleys are then media blasted for a satin silver finish and lasered with the Agency Power name (not shown). Our Agency Power pulley weighs about 3.5lbs lighter then the factory pulley. Reducing rotating mass gives the Scion TC a gain of 10 horsepower and an increase in torque by 11 ft/lbs as Dyno proven. Availability: Usually ships in 5-7 business days.