In general, what is NOT a feature of ENT?

The correct answer highlights that underground usage is not a typical feature of ENT (Electrical Nonmetallic Tubing). ENT is primarily designed for above-ground applications because it is lightweight and has a flexible nature, making it easier to install in various environments, particularly in residential and commercial buildings.

While ENT does provide electrical insulation, which is crucial for safety, and is built to withstand exposure to harsh conditions, as a nonmetallic conduit, it does not generally offer the structural integrity required to be buried underground where it may be subject to physical stresses or pressure from soil or other elements.

In contrast to other conduits that are specifically designed for underground installation, ENT is used mainly in situations where it is exposed to the elements but not buried. Thus, stating that it can be used underground does not align with the intended use and features of ENT.