New Anti-Terrorism Barrier Combines Simplicity with Massive Vehicle Stopping Power. Ideal product for port security. The company that designed the first portable vehicle barrier and the first barrier using lightweight energy absorbing material instead of heavy steel components, is introducing a new hybrid design unlike any existing anti-terrorism barrier. PRO Barrier Engineering's VolarXTM uses a gravity-propelled roller design to stop vehicle-based attacks and provide explosion protection. The name derives from Latin terms for rolling fortress. According to Dr.