Fuel rail upgrade kit for NISSAN SKYLINE RB25 Motor -Direct bolt on -Allow tuner to use larger top feed injectors -Best for high boost and tuned vehicle -Fits 10.5 to 11 mm top feed injectors This fuel rail upgrade kits are high-performance fuel delievery unit that are designed to properly supply the additional fuel needed for high performance / boost applications. this fuel kit is direct bolt-on replacements of factory fuel rails, this allows tuner to use larger top-feed injectors. This fuel rail are machined out of aluminum and anodized.