What typically characterizes the warhead of the PG-7 Nader?

The warhead of the PG-7 Nader is characterized by a double metal skin. This design feature enhances the warhead's ability to penetrate armor by allowing it to contain a shaped charge that focuses the explosive energy more effectively. The double skin construction helps to create a more powerful jet of molten metal upon detonation, which increases its lethality against armored targets.

In contrast, options like a single metal skin would not provide the same level of efficiency in energy focusing, while a heavy tungsten core is typically associated with penetrator designs rather than shaped charges like the PG-7. Similarly, a plastic casing does not align with the intended function of the PG-7 Nader, which requires metal for structural integrity and effective penetration.