Find a huge variety of Silicone Couplers & Boots you need to finish your project 2016-2022 Chevy 2.8L Duramax. You can find the coupler you need, whether you need a reducing, hump, straight, or angled boot with a 45�90 degree bend. These couplers are constructed with durable rubber or silicone and are reinforced for greater strength. You can find couplers ranging in size from 2� all the way up to 6� diameter. Vibrant, PPE, Full Send, and Mishimoto are the brands available at XDP.