The Fernco 4" x 4" Donut (Model A426-405) is a versatile plumbing accessory designed for connecting pipes of different materials. This donut is crafted from high-quality rubber, ensuring a tight seal that prevents leaks and maintains system integrity. With a size of 4 inches, it is perfect for use in various drainage and sewer applications. The donut is easy to install and compatible with both PVC and cast iron pipes, making it an essential component for any plumbing project. Its durable construction meets industry standards, providing long-lasting performance.