Find the Intake Couplers & Elbows you need to complete or repair the cold air intake system on your 2011-2016 Chevy/GMC 6.6L LML Duramax. Manufactured out of rubber, silicone, or plastic, these couplers come in various sizes ranging from 3.5" all the way up to 6" diameter. You will find a vast selection of hump, straight, reducing, and 90-degree couplers. XDP carries top manufacturers such as Fleece Performance, Vibrant, Grand Rock, and AFE.