Find the Intake Couplers & Elbows you need to complete or repair the cold air intake system on your 2007.5-2010 Chevy/GMC 6.6L LMM Duramax. You will find a vast selection of hump, straight, reducing, and 90-degree couplers. These couplers come in various sizes ranging from 3.5" all the way up to 6" diameter and are manufactured out of rubber, silicone, or plastic. XDP carries top manufacturers such as Fleece Performance, Vibrant, Grand Rock, and AFE.