These Black Anodized Exhaust Trim Rings will give an extremely clean finish to the body panel you are passing your exhaust through (see picture in ad). For safety and weight reasons it has become very popular for turbocharged, supercharged, nitrous, as well as naturally aspirated cars to run exhaust out of your fenders/or other body panels instead of shooting exhaust on the ground where it can potentially spray oil, fuel, or moisture on the ground where your tires will run over it. These rings are cnc laser cut and are 4" ID which gives a perfect .25" on each side of a 3.5" exhaust pipe passing through. Included in the kit are two stainless trim rings, as well as 1/8" pop rivets for clean and secure installation.