I just love my new vacuum cleaner. It is a Sears Kenmore Intel Clean Vacuum. I have spent many, many hours the last few weeks making sure my house is "Intel Clean". There is a sensor that tells you when there are particles going thru the tube. If there are a lot, the button is red. If there are some, it is orange and when there are little to none, it is green. Just had to share. If you are in the market for a new vacuum cleaner, I highly recommend this one.