The 603-L is a Self Closing Straight Stop from Union Brass Manufacturing Co., featuring a 3/8" - 18 thread and a convenient lever handle. This high-quality brass stop is designed for durability and reliability in plumbing applications. Its self-closing mechanism ensures efficient water control, making it ideal for various residential and commercial settings. The robust construction provides excellent resistance to corrosion and wear, ensuring long-lasting performance. This fitting meets industry standards for quality and safety, making it a reliable choice for any plumbing project.