These are great for use with wire harnesses, other wiring, hoses or lines going through firewalls or other bulkheads in your vehicle. There is no need to disassemble existing lines to install these seals. The two piece design easily fits together for simple installation. 4-1/2" outside diameter with no inner hole, cut to fit your application. Can cover holes as large as 3-3/4". Made from a combination of fire-retardant rubber and anodized aluminum bezel. Keeps unwanted smoke and fumes from entering the driver's area. Protects lines or wiring from chafing and abrading on rough surfaces. They make a great finishing touch for your project. The unit comes in two half-part sections so that it can be mounted on an existing installation without disturbing anything. Installs with rivets or screws (not included). Qty 2 grommets