Bag In Bag Out Filter, that is, bag in bag out filter, usually referred to as BIBO, also known as pipe type exhaust air efficient filter device. Since the filter has intercepted harmful aerosols with high activity or high toxicity during the working process, it is necessary to ensure that the filter does not have any contact with the external environment during the replacement process, and the filter replacement is carried out in a sealed bag, so it is called the bag into the bag filter. Its use can effectively prevent the diffusion of harmful aerosols and avoid biohazards to personnel and the environment. It is a filter device used for specific biological risk environments to remove harmful biological aerosols in the exhaust wind. It generally has the function of in-situ disinfection and leak detection.