What type of cable features a flexible metal sheath for protection?

The type of cable that features a flexible metal sheath for protection is armored cable. Armored cable, often referred to as AC or BX cable, utilizes an outer layer of metal, typically made of aluminum or steel, which provides physical protection against damage and environmental factors. This metal sheath is flexible, allowing for ease of installation in various settings, including areas where cables might be exposed to impact or abrasion.

Armored cable is particularly valued in situations where additional durability is necessary, such as in commercial and industrial environments. It also helps to provide some level of grounding due to the metallic sheath, enhancing electrical safety. The use of this type of cable is compliant with various electrical codes, making it a reliable choice for many electrical installations. Other cable types mentioned do not have a flexible metal sheath; for example, Romex is a non-metallic sheathed cable, while FEP cable is designed for specific applications with chemical and heat resistance but lacks any metallic protective layer.