A brass 45-degree elbow is a plumbing fitting used to create a change in direction of a pipe by 45 degrees. The 45-degree elbow is designed with female threads on both ends, allowing for a secure and tight connection. The brass construction ensures durability and longevity, making it suitable for both indoor and outdoor use. The 45-degree elbow provides a smooth and gradual change in direction, helping to minimize flow resistance and maintain optimal water flow.