DNA Motoring DNACOILDPMM90GDBK Suspension Coilover Damper Shocks Kit [For 89-05 Mazda Miata] High quality CNC machined steel (Springs) and aluminum (shocks) construction Pillow ball upper mounts with rubber dust boot covers and dual locking spring perch applied Reversed Mono-shock and single-cylinder design Improved ride quality and handling Front spring rate: 7.00 kg/mm; Rear spring rate: 6.00 kg/mm