I work at a recreation center and there are 4. I use one of these that they gave me at the facility. It does the job incredibly well! There are several exercise machines on a large area of the carpet and it is almost never vacuumed. I do this once a month and every time I clean it I get a full bag. The other machines start normally even with full sacks, but still work perfectly. The tools and the suction power are amazing! The rectangular brush helps remove dust in crevices, gaps or situations where a regular round brush would not fit. Replacing the strap is very easy, and the seal on the disposable bag helps keep dust out when thrown away. The cable is good because if you damage it you can just plug in a new extension instead of having to remake it. All in all this is a GREAT car!