NOT TO BE USED ON THE LOW PRESSURE SIDE OF MECHANICAL FUEL PUMPS (INCLUDING DIRECT INJECTION.)The opening and closing of the injectors creates pulses in the fuel rail, which can lead to unstable fuel pressure. This damper should be used (especially with high flow injectors) in order to achieve a safe and consistent rail pressure. The internal diaphragm will absorb oscillations and smooth fuel pressure. This correction can be measured throughout the RPM range and can often help an erratic surging idle. This OEM quality damper features a 3/8" NPT male thread with impregnated pipe thread paste. SPECIFICATIONS Optimal Range: ~3bar (43.5psi)Overall Height: 45mm (1.8")Wrench Hex Size: 22mm Threads: 3/8"-18 NPT Metal Color: Varies