Ideal for heavy-use applications, where mill operation is more than 5 hours/day. On-line filter-cleaning function allows clinician to operate the mill overnight while the filters clean themselves. HEPA filter for 99.97% efficiency at 0.3 microns. AutoFlow feature can be set to the lowest acceptable speed, and the motor automatically speeds up to overcome pressure increase. One powerful brushless motor with a separate access door allows debris to be removed without having to access the filter section. Its 20,000-hour motor life requires virtually no motor maintenance. Silent operation: one of the quietest units on the market (55dbA at high speed). Also included: both 4-pin and 6-pin interface cables for all VHF milling machines.