All the metal components on E90 rear suspension are from high strenght steel

Inlet Hose Adapter 1-1/2' OD

This center cap only fits: JRX1 and JRX2

The Dual Port is a 50-50 recirculation/vent-to-atmosphere valve for that classic vent-to-atmosphere BOV sound at high boost and quiet operation at low boost

Clutch Kit - Xtreme Performance Heavy Duty Organic 560kg (40% inc.) KMI19001-1A JR14 All the metal components onXtreme Performance sprung organic kit 1A Recommended for: Street use in vehicles with minor engine modifications. Sprung organic clutch kits offer exceptional driveability for vehicles used daily but also have performance modifications. The sprung organic disc offers improved dampening which reduces the shock loading on the transmission. Specifications: Torque capacity Nm Clamp load 560kg 40% Increased over standard Organic Friction Discs Heavy Duty