SZ Series dampers are 46mm steel monotube shock absorbers with versatile usage in many forms of racing. Available in a range of linear and digressive valving options and stroke lengths, these shocks are ideal for applications where racer rebuildability is not required or allowed. Proprietary spring steel valving discs provide superior damping during high frequency spring oscillations. Bilstein's spring steel, high metal memory valve discs also outlast all other brands, require far less maintenance, and eliminates the gradual degradation of shock performance commonly seen in the race shock industry. Spring steel valve discs helps your car have more entry speed, more corner speed, greater exit speed, and lower lap times.