What type of construction is used for the cylinders mentioned in the flash cards?

The correct answer is composite construction because it refers to materials that combine different substances to achieve superior properties compared to individual materials alone. In the context of cylinders, particularly those used in firefighting and safety gear, composite construction typically involves a combination of materials such as aluminum or steel with fiber-reinforced plastics. This combination allows the cylinders to be lightweight yet strong, providing enhanced durability and resistance to impact and environmental conditions.

This construction method also allows for better pressure handling, which is critical for cylinders that may store gases or liquids under high pressure. The use of composites helps in reducing the overall weight of the cylinder, making it easier for responders to carry and manage during emergencies while maintaining safety standards.