Mega-Forcefield Bubble
From Multiversal Omnipedia
The Mega-Forcefield Bubble was a device used by Dark Kat to capture the Swat Kats and a few other hostages. It has the unique quality of being impenetrable on the inside but not the outside. In other words, the subjects on the inside could be shot at through the field, but the shot would then ricochet indefinetly on the inside. This would actually explain how the Swat Kats were able to breathe while inside.
