Connectors with cable entry conforming to industry standard EN 175301-803 (formerly DIN 43650) are commonly used to power solenoid valves. Connectors are rated for protection, etc., IP 65 (in line with IEC 60529), which means reliable exposure to fluids and dust for performance when properly assembled with washers and finished packing screws. Solid type contacts are made of silver-plated brass. It takes special care with the newly designed contact pins and wires to provide protection between them to prevent damage to conductors during assembly and as a result provides a completely secure connection. A circuit diagram is printed on the outside of each connector to help identify the circuit. Mechanical springs provide a secure and sturdy assembly between the contact bracket and the housing.