Connector contacts: Brass with gold plated,r, It has good conductivity. Rated voltage: 60V, Current per contact ( 40 °C ): Max 4A, Insulation resistance: ≥100MΩ, Contact resistance: ≤3MΩ, Temperature range ( Insulator / Wire ): -28 to 85°C / -30 to 80°C. Widely used in aviation, navigation, construction site, port, dock, and some other sealing electronic equipments. Waterproof, weatherproof and really a great apparatus electronic connector.feature with quick design. What is in the package: 4* Male Aviation Plug