I was looking for a vacuum cleaner with manual height adjustment for my "shaggy" carpet. I read all the reviews about this model and decided to try it. Although it says "commercial" here, I was expecting something better than mostly plastic parts. Although I saw the inferior plastic construction of this vacuum cleaner I understood our changing world, when I opened the box I decided I would leave it on the condition that it sucks well. I tried shag in our bedroom. It picked up dust very well. This thing really has amazing suction power! So far, so good. Then I took it to my home office where the carpet is lower and not shaggy. I turned the manual height adjustment from 6 to 4. Still not low enough so I went with 3 or less. This is when the thumbwheel decided to "hang" and not go to the lower positions. I remember reading a review that they had trouble with the dial. As this issue came fresh out of the box and I could already see that the build quality of this vacuum is questionable I decided to return it. It's a shame. Sanitaire used to make quality stuff, but this isn't an example. The price of 300β¬ is definitely not worth it.