The Waterway 417-5040 union tailpiece is designed for compatible plumbing applications using a 2 inch buttress thread connection and a 2 inch slip tailpiece. A tailpiece like this is useful where the union connection needs to remain serviceable while continuing into a rigid 2 inch solvent-weld line.This Waterway part is especially practical when the tailpiece has worn out but the rest of the union assembly is still usable. Replacing the correct half of the connection can help restore function, fit, and easier future service without unnecessary extra parts.For compatible union repairs and rigid plumbing service, this Waterway tailpiece is a practical replacement when a 2 inch buttress-thread-to-slip connection is needed. Waterway union tailpiece 2 inch buttress thread x 2 inch slip tailpiece Useful for serviceable rigid plumbing connections Helps restore the plumbing-side union fit Supports cleaner and more efficient repair work