RTS Explosion Proof billet steel flywheels are designed from the ground up to deliver high performance results. Starting with CAD engineering and tested to limits far above the SFI-ratings, these flywheels are then constructed from 4140 high-quality materials to ensure reliable results. These flywheels are sure to deliver what they promise: Features include: CAD engineered 4140 Steel and heat-treated ring gears Available in standard finish or with a black oxide anti-corrosive finish CNC-machined finish 29.7 lb weight Available in multiple configurations Note: The black coating is a black chemical conversion coating (not physically coated) and will not affect clutch discs.