Find a huge variety of Silicone Couplers & Boots you need to finish your project 2003-2010 Chevy/GMC Kodiak/TopKick 6.6L Duramax. You'll find straight, reducing, hump, and angled boots ranging from 45 to 90-degree bend to choose from. These reinforced couplers are manufactured with durable rubber or silicone for increased reliability. You can find couplers ranging in size from 2" all the way up to 6" diameter. PPE, Vibrant, Mishimoto, and Full Send are just a few of the top brands available from XDP.