What is a characteristic of liquid-tight flexible metal conduit (LFMC)?

Liquid-tight flexible metal conduit (LFMC) is designed with a characteristic outer layer made of a liquid-tight thermoplastic, which provides protection against moisture and liquids. This feature allows LFMC to be used in environments where exposure to water or other liquids may occur, making it suitable for various outdoor and indoor applications. The combination of the flexible metal interior and the thermoplastic exterior gives LFMC its unique properties, combining the advantages of flexibility for easier installation with the added benefit of being protected from environmental factors like water.

The other options do not accurately describe LFMC's characteristics. For instance, LFMC is not made entirely of rubber, nor is it classified as a type of rigid conduit; instead, it is inherently flexible. Additionally, LFMC is not restricted to indoor use only; its design allows it to be utilized effectively in outdoor environments as well. This versatility further emphasizes the importance of its liquid-tight feature.