The Specna Arms Gun Case has been available at most airsoft retailers in Europe and it is a good seller. Made of polymer, it is a hard case rifle that can protect your airsoft gun with a  4-layer insulation material that can be cut individually, 4 flap locks to close the case tight, air pressure valve to vent the case, and it is IPX7 rated waterproof. Tom's Airsoft Channel got one just for this video review (in German).