When replacing dust collector bags, installation of the last bag or two can be difficult- they are packed very tightly against one another. This tool is designed to make the job much, much easier. It spreads the hanging bags apart, compressing them and making room for additional bags. To use the tool, simply insert the ends into 2 adjoining bags, then tighten the bolt with a wrench. When the bags have spread apart sufficiently, just insert a new bag.