EFT Racing Lightweight Chromoly Flywheels are made from 4140 one-piece billet chromoly steel. They are specifically designed to reduce weight and inertia for better engine response. Most incorporate special design features to enhance the air flow to improve the cooling of the clutch. The ring gear teeth are milled onto the flywheel unlike an aluminum flywheel where the ring gear is pressed onto the flywheel which has the possibility of separating from the flywheel. All EFT Racing Chromoly flywheels have passed engineering tests to 12,000 rpm. After professionally installed the flywheel requires a 500 mile break-in period. - Ultra heavy-duty and weighs only 8.5 lbs - Meets or exceeds SFI 1.1 specification - Made from 4140 forged chromoly steel (2X stronger than billet steel) - EFT Racing Lightweight Chromoly flywheels incorporate special design features to enhance the airflow for improved clutch cooling - EFT Racing Lightweight Chromoly flywheels work with every clutch including Exedy, ACT, Fidanza, Clutchmasters, F1 Racing, and other direct replacement clutch kits - CAD designed, CNC machined and computer balancedVehicle ApplicationFits 1990 - 2005 Honda Civic (1.5L D15, 1.6L D16, 1.7L D17 SOHC 4cyl)Fits 1993 - 1995 Honda Civic Del Sol (1.5L D15, 1.6L D16 SOHC 4cyl)Fits 1990 - 1991 Honda CRX (1.5L D15, 1.6L D16 SOHC 4cyl)