The Grand Rock 8 Inch Length Pipe Reducer is a practical and versatile solution for reducing a 4-inch diameter I.D to a 3 1/2-inch diameter O.D. Made of durable aluminized material, this 8-inch long pipe reducer is designed to fit most makes and models. Its 4-inch ID reduced to 3.5-inch OD feature makes it a reliable and efficient choice for various applications. Sold individually, this pipe reducer offers a cost-effective and convenient solution for your piping needs.