If you have a hard shell case, open it up and look at what is inside. Some foam padding, a small bag, bow holders... PETRUS could have been just another hard shell case like that. While some would prefer only light cases, PETRUS took a completely different approach in its interior design to provide a whole new level of uncompromised protection. Air is one of the lightest and most effective suspension methods, and is already widely used in safety applications such as airbags, packaging solutions, shoes, and many others. Under the soft-suede covered neoprene cushion, the violin is protected by specially designed air bubbles called Aircell®. While the strong carbon fiber shell of the PETRUS protects against extreme physical impacts from outside, the specially thermoformed inner shell completed with Aircell paddings will absorb the shock caused by an impact with excessive G-force.