Quiet Cube™ technology is now available on our Diesel Hurricane 500 Vacuum. The new QC500 is the quietest diesel-powered vacuum ever produced. 86 Dba at 3 feet at full vacuum (27Hg). Now you can work in the city, in the suburbs, and in the morning without disturbing the residents. Trailer and truck-mounted vacuums have always been notoriously loud, causing contractors and facilities to work specific hours and deal with complaints. Now you can work where you want, when you want, with the NEW Hurricane QC500 “Quiet Vac”.