The ACT Prolite Flywheel for the Nissan 350z / Infiniti G35 is made using premium quality, forged chrome-moly steel that is then CNC machined then balanced. The ACT Prolite flywheel has more material removed from the outer rim than the Streetlite to get it down to it's super-light 13.2lbs. If you are planning to daily drive your 350Z/G35 on the street, in traffic, you do not want this light of a flywheel. The Prolite is a RACE ONLY flywheel. The Prolite also features an induction-hardened integral ring gear, and is durable and thick enough to be resurfaced. Certified to SFI Specification 1.1.