The RB900 is a very high quality 2HP 900 CFM cartridge style dust collector. This heavy duty collector is built entirely from 12 gauge steel and is 100% hand welded. This means it has no seems that can leak dust. The pleated cartridge filter is loaded from the top of the cabinet which is a very unique design that ensures a tight seal. Cleaning the filter is accomplished automatically by a reverse pulse system that has a digital timer which pulses the system at a preset interval. This insures that the filter is functioning at its highest level at all times. The sump is then emptied from the bottom of the collector.