The 4" Cast Iron Tapped Screw Ferrule with a 3-1/2" tapping size from Braxton Harris is designed for secure connections in plumbing systems. Made from durable cast iron, this ferrule provides strength and longevity. The tapped design allows for easy installation and compatibility with various fittings. With a size of 4 inches, it is suitable for both residential and commercial applications. This ferrule meets industry standards for quality and performance, making it a reliable choice for plumbing professionals looking for durable and efficient solutions.