As an industrial and scientific buyer, I highly recommend these lead-free 4 inch fittings for pneumatics and plumbing. According to my experience, the Watts LF7RU2 fittings are exceptionally durable and provide a secure connection without any leaks.The one-piece design makes installation a breeze and the fittings are suitable for both hot and cold water systems. However, the price may be slightly higher compared to other brands, but the superior quality justifies the cost. Overall, I am very satSee full review