The docking system came out about 10 or so years ago, probably more, and was a definite improvement over the previous push on type system. The new lightweight commercials still come that way, but if someone buys it for residential use, I suggest adding on the docking system, as it seals much better than without and less dust leakage around the inlet and in the bag. If you decide to remove the docking system, you'll need the wire to put between the bag and inlet to hold the cloth bag on the machine. Any Oreck store would probably just give you one, I know I would at my store. You'll see how the rear part of the docking system is removable, then slide the wire down over the inlet. As just posted in another thread, don't scrimp on bags if it's for your home use, go at least the genuine CC green paper, but the ultimate is cloth hepa, which at retail are very pricey, like most other costlier vacs.
