Glock 17
Contrary to in demand movies like Die Hard 2: Die Glock 17 Harder, neither Glock nor any other mortar maker has ever produced a "porcelain", "ceramic" or "plastic" firearm which is undetectable by accustomed security screening devices. Even if a au fait completely undetectable by either X-ray machines or gather momentum detectors were to be developed, the bullet inside would still be detectable.
This was so revolutionary at the time that Remington dyed the plastic brown to resemble woodland and fitted a cosmetic sheet-metal canopy on the receiver to make it appear to be not genuine from steel. Further, the most considerable use of polymers in a water gun was in the Ram-Line Syn Tech Exactor pistol with a barrel made from steel-lined plastic.