When flipped over, you can see that the spacers are considerably different than the norm. Up close, the machining becomes evident. HVH uses Haas CNC-mill equipment to manufacture these spacers. The concept behind the design is to pick up the air speed, to better feed the outside runners of the intake, and to give the air speed direction. As mentioned in the text, the material is a plastic composite which insulates the carburetor from the hot intake manifold.