afe Magnum FORCE Intake Coupling Kit (4 IN ID to 4-1/4 IN ID x 90 Deg.) Elbow Coupler - Black4 1 4 IN to 4 IN Reducer: This coupling features a 90 Degree angle and is designed to connect to tubes with a 4 IN and 4 1 4 IN diameter. It's commonly used on aFe POWER cold air intake systems, but can be used for a variety of projects. Silicone Construction: Its silicone construction features four layers of polyester reinforcement, making it less prone to deformation, tearing, and other damage, than average couplings. Its extreme durability makes it