The T&S Brass B-3990-01 is a modular waste drain valve designed for efficient drainage in sinks. It features a convenient pull handle for easy operation and is compatible with a 3-1/2" sink opening. The valve includes a 2" NPT female and a 1-1/2" NPT male adapter, ensuring versatile installation options. Additionally, it comes with an overflow tube and head assembly, providing a complete solution for your drainage needs. This product combines functionality and reliability, making it an essential component for any plumbing setup.