A brass reducing coupling is a plumbing fitting used to join two pipes of different sizes together. The reducing coupling is designed with female threads on both ends, allowing for a secure and tight connection. It features one larger female end and one smaller female end, enabling the transition from a larger pipe to a smaller pipe. With their sturdy construction and brass material, brass reducing couplings offer durability and longevity, contributing to the efficient and reliable performance of your plumbing system.