This aluminum tube nut and sleeve is designed for securing 3/8 inch hard line tubing in water cooling systems. Made of durable aluminum, it features precision machined threads that ensure a snug, leak-proof connection between tubing and fittings. The black anodized finish protects against corrosion and looks great as part of a stealth build. Installation is quick and easy with the included sleeve that slides smoothly over tubing for a finished look. With a quality construction and simple design, this tube nut keeps your cooling loop sealed and performing at peak efficiency for years of use.