The Competition Clutch Forged Lightweight Steel Flywheel is replacement for all 2004+ STI. The lightweight flywheel weighs 15lbs 

*Qualities of the CCI Lightweight Steel Flywheel*
* Preserves low end torque and drive ability
* One piece ring gear for high durability
* Well suited for Stage 1 and Stage 2 clutch kit applications
* Stamped with 4140 plate with 2000 ton pressure at 1260 degrees
* CNC machined and balanced to O.E. specifications

Reduced Mass = Increased Acceleration

Meets and exceeds SFI 1.5