Black Silicone Air Intake Boot (MMHOSE-E36-92IBBK) by Mishimoto. Includes: Silicone Hose. Inner Diameter: 2.90in & 3.10in. Outer Diameter: 3.30in & 3.50in. The Mishimoto Silicone Intake Boot is made from a combination of high-grade silicone and heat-resistant embedded fibers for a high-quality replacement kit for your OEM rubber hoses. Mishimoto silicone hoses retain OEM fitment while providing increased pressure tolerance for the ultimate upgrade in performance and style.