If you’re lucky enough to own a Hoover Concept One vacuum congratulations. Hoover introduced this vacuum in 1978. Ironically this is the exact year I started my career with the Hoover Company. This vacuum replaced the Dial-A-Matic which was ahead of it’s time. The Hoover Concept One came in a self propelled, and a non self propelled model. The non self propelled model originally was made under the model number u4203 ( brown no automatic cord rewind), and model u4201 ( blue with automatic cord rewind). The self propelled models were a u3103 (same as the u4203 but self propelled), and u3101 ( blue self propelled with cord rewind). The non self propelled vacuums had only one belt which turned the agitator. The self propelled vacuums had two belts. One to turn the agitator, and another belt to drive the self propelled feature. These vacuums used an A style bag. It loaded from the top, and deposited the dirt in the bottom. This bag system allowed the vacuum to maintain peak efficiency whether it was a new bag, or a bag half full. The agitator used was a totally new invention for Hoover. It was called a Quadraflex agitator. This simply meant the vacuum had four brush strips on the agitator versus the two brushes standard in all other vacuums. It gave the operator twice the sweeping action on the carpet, and performed very well. The rear wheels were very large allowing it to be easily pushed through the thickest of carpets. The vacuum had a self adjusting head, but also allowed the head to be raised into a fixed position for shag carpets. This vacuum was very innovative for it’s time, and was a huge success for the Hoover Company. They made this vacuum under various model numbers for over a decade. If you own one of these vacuums, and need bags click on www.okvac.com If you need belts or other parts click here for help.