These baffles were designed for vehicles such as Cobra's and Corvette's with side pipes. These will fit into a 4” Cobra side pipes, and Hooker 4” side pipes. These mufflers flow at an extremely high flow rate. The core is up to a 3”" core, which is the largest side pipe core available anywhere. The mufflers are packed with a high-temp performance muffler packing (see second photo). Fits up to a 4"” side pipe system. Easily removed for racing. Unlike other mufflers, these are re- packable. Extremely light weight compared to other side pipe mufflers. For Cobra Side Pipes 22” Long For Corvette Side Pipes 30” Long Other sizes available. Custom built to order. Approximately 5-7 days. Call for details. 972-937-7735 Ken ALL SIZES SOLD AS A PAIR.