Complete fit test in 2-3 minutes! Test in any environment with no consumables using OHD's Controlled Negative Pressure Technology. Within seconds of testing, the Quantifit can determine whether the user has a basic fit or not. If other quantitative fit test instruments measured accuracies of less than 40 percent, why put your employees at risk? For more information go to http://info.ohdusa.com/the-benefits-of-switching-to-cnp