The Grand Rock 8 Inch Length 4-7 In Diameter Pipe Couplers CP-358C are a practical and versatile solution for connecting pipes of varying diameters. Available in 4, 5, 6, and 7-inch inner diameters, these chrome couplers are sold individually and are 8 inches long. Made of aluminized steel, they are durable and fit most makes and models. With a range of diameters from 2 inches to 8 inches, these pipe couplers are a reliable choice for a variety of applications.