aFe 07-13 Chevrolet Silverado 1500/GMC Sierra 1500 Silver Bullet Throttle Body Spacer - SilverBrand aFe Part Number 46 34019 Category Air Intake Systems Throttle Body Spacers Condition Brand New Original Manufacturer Packaging The serrated helix design creates air turbulence in the intake manifold. This turbulence increases the air pressure in the combustion chamber, resulting in increased performance and improved throttle response. The serrated helix combination design also reduces intake whistle that occurs with helix only designs (US PAT