Find a huge variety of Silicone Couplers & Boots you need to finish your project 2019-2023 Ram 6.7L Cummins. For increased strength, these silicone or rubber boots are reinforced to deliver a long service life. From 2" all the way up to 6" in diameter, you'll find the coupler to fit your needs. You can find the coupler you need, whether you need a reducing, hump, straight, or angled boot with a 45 to 90 degree bend. PPE, Vibrant, Mishimoto, and Full Send are just a few of the top brands available from XDP.