PB-2850ATBORX Porta-Brace Wheeled Audio Cart Hard Case. Constructed with a high-performance hard-resin material reinforced at the corners. Wheeled Hard Cases are smooth rolling, ideal for combining video, audio, and photographic equipment for transportation and protection. The PB-2850ATBORX is not a watertight / airtight case due to the process of adding the custom off-road wheels and axle. The case does not lose any protective strength or integrity but it will allow air to the main storage area.