Which of the following items may require preservation to prevent corrosion?

Electrical connectors are critical components in avionics systems and are particularly susceptible to corrosion due to their exposure to environmental factors such as moisture, salt, and other corrosive elements. Preservation techniques, which can include coatings, sealants, or protective greases, are essential for ensuring that electrical connectors maintain their functionality and electrical conductivity over time.

Corrosion in connectors can lead to poor electrical connections, increased resistance, and ultimately failure of the avionics systems they support. Therefore, proper preservation methods help maintain the integrity and reliability of these systems, making it vital to address corrosion prevention specifically for electrical connectors.

While other items listed might also require preservation, they do not have the same level of vulnerability or impact on the performance of avionics systems as electrical connectors do.