Integrated Engineering Phenolic Large Port to Small Port Adaptor KitSmooth transition between manifold and cylinder head port sizes Decreases intake temperatures and increase horsepower 12. 5mm thickness decreases heat transfer drastically Easily install your IE Transverse 1. 8T Intake Manifold on a small port head TECHNICAL DETAILS IE's phenolic transition spacer for your 1. 8T engine delivers a smooth transition when installing a large port intake manifold to a small port cylinder head. The 12. 5mm heat resistant