Material: Zinc alloy or Alluminum Alloy just according to your requirement.

Watertighten Zinc Thread Electrical Connector (DPN-1)Property:
1. Inner threaded connector
2. For the connection of felxible pipe, equipment, electrical box
3. Water resistant, anti-corrosive.
4. Galvanized type, chromium and nickel plated also available.
5. The hex nut thread smoothly into the connector body.
6. Reliable quality
7. Stable perfermance.
8. Size available: 3/8"--6"