The 5 Inch OD To 3.5 Inch ID Aluminized Reducer is a durable and practical solution for reducing exhaust pipe sizes. Made of aluminized steel, this reducer features a 5-inch outer diameter (Measurement A) and a 3.5-inch inner diameter (Measurement B), with an overall length of 8 inches. Sold individually, this versatile product fits most makes and models, making it a convenient and reliable choice for your exhaust system needs.