This is a commercial grade vacuum intended to be used to groom horses, not meant for regular vacuuming. I have one that needs motors (mine has seen kinder days, as well as having been repainted once) and just has the large upholstery tool looking attachment. The box inside isn't for storage, its part of the dirt containment setup. The air is directed into the box at an angle like on a Compact, making the air swirl around in the box just like it does in a Compact bag, leaving as much dirt there as it can, and then it has the cloth bag behind that. They have 2 motors in series, individually switched. I suppose one could find a way to attach a PN to it, but I don't plan on doing that with mine, I want to get some new motors, and maybe see about setting up a disposable bag in it, with the intention of creating a very good and powerful bag cleaning vacuum for my cloth bag vacuums. I hate cleaning bags, this could make it easy and it could easily inhale the complete contents of lets say my Hoover 305 Special's bag as well as vacuum the bag clean of all the dust without be having to breathe any of it.