Made of brass, this Watts compression T-Fitting is designed for strength, durability and rust resistance. It has three compression ends, each with an outside diameter of 3/8". The tee fitting is ideal for use with any tubing soft enough to accept a clamp style connection, including vinyl and rubber. It is typically used for gasoline, grease, oil, water, vacuum and air line applications. The fitting is not recommended for use with steel tube.