aFe Power Silver Bullet 46-31001 BMW X5 (E53) Throttle Body Spacer In-house dyno testing resulted in max gains up to +10 HP and +14 lbs. x ft. of torque Precision machined from 6061-T6 billet aluminum Serrated/Helix Combination Design for optimum airflow into the combustion chamber Works with OE and aFe Power cold air intake systems This product is 50-state legal (CARB E.O Number D-550-11)