Sachs 312 496 Shock Absorber For added durability, Sachs Micro-Polished Chrome Piston Rods have been hardened for maximum strength to provide the longest service life. Our chrome finish helps fight rust while the low-friction surface effectively prevents seal leaking For added comfort and performance, our engineered polymer piston band immediately responds to suspension movements even at slow speeds. The piston band effectively seals the working cylinder allowing the valves to operate at 100% efficiency.