Torque Solution HD Cam Gear SetTorque Solution HD Cam Gear Set for Subaru EJ207 EJ25 Single AVCS Exhaust cams. They replace the OEM plastic composite cam gears that become brittle over time and may fail causing major engine damage. Our gears are made form 7075 T6 billet aluminum due to its strength. We wanted to ensure these will last you a lifetime. These are a must for built engines running a stiffer valve spring which causes more stress on the cam gears. Features: 7075 T6 Billet