Not too much to get excited about. This is a filter. When the vacuum cleaner sucks in the solids you want to remove from the surface, it creates a low pressure air zone and uses a filter to separate the solids from the air. Solid particles remain in the vacuum cleaner until they are emptied. The filter can be washed with soap and water, air dried and reused. It's a good idea to have two filters - use one while the other dries. The original filter lasted much longer than the original battery…