Impervium generator

An Impervium generator is a device used by Krang in the 1987—1996 animated series episode Four Musketurtles.

When Impervium is placed in it, it can generate a forcefield around its suer, so no weapons can harm or use it. Krang has fit the forcefield for his size, when in the Bubble Walker, something Shredder notices when trying to steal it.