The LA2-A does not use fabric bags as postive pressure plenum is surrounded by negative ones. It has ULPA filters with extended life, one for supply and another for exhaust having almost 100 percent filtering effectivity with 0.1 to 0.3 microns particle size. For optimum downflow consistency, the supply filter is installed at angle parallel to the profile of the cabinet. By simply turning the sash window to the right position, you turn on or off the blower and the lights. In addition, it comes with RS 232 data output port which makes remotely controlling or monitoring parameters possible. The sash has no frame and the work surface is detachable so cleaning is no hardwork. And to provide more comfort and accessibility, the front is conveniently angled.