KYB Shock Absorber - Left Hand Rear - MR-S ZZW30Excel G Shock Absorber for MR S ZZW30 Left Hand Rear Twin tube gas shock absorber Patented valving plus pressurized nitrogen gas account for riding comfort and, at the same time, dramatically reduce the aeration or foaming that commonly occur in shock absorber and cause its performance to start fading, even after only a few minutes in operation. Fensport Tip: It is advisable to always replace shock absorbers in axle pairs to retain handling balance,