The NST Lite series is a designation used for pulleys that are light-weight versions of their OEM counterparts. All NST pulleys are built using High quality 6061-T6 aircraft aluminum and are easily 60% to 70% lighter than steel or cast iron OEM pulleys. The NST Lite series is designed for owners looking to reduce weight and increase the throttle response of their engines. These OEM-diameter pulleys will neither underdrive nor overdrive the associated accessories but still lead to great throttle response and improved horsepower numbers in many applications. Each NST Yaris Kit is carefully crafted from 6061-T6 aircraft aluminum, tested and balanced to high tolerances. Every NST pulley is hard anodized for exceptional durability and is a great item for use at the track or on the street. Available in your choice of colors: Red, Blue, or Graphite Gray. BENEFITS Great weight reduction - Average of 70% over OEM! Increased horsepower - Average of 6 - 8 horsepower Lower ET's & higher trap speeds - Average of .20s & average of 2MPH