Meet the unique Esco Dynamic Unique Esco Dynamic Chamber™ plenum - doesn't use fabric bags; negative pressure plenum surrounds supply positive pressure plenum. Its features include : - Long-life supply ULPA filter (per IEST-RP-CC001.3) with >99.999% efficiency for particle size between 0.1 to 0.3 microns. The angled supply filter matches cabinet profile to achieve best downflow uniformity. - Esco Sentinel™ microprocessor. Frameless, shatterproof sash is easier to clean. Ergonomically angled front improves reach and comfort. Actual work access height is 45 mm (1.8”) higher than tested sash opening providing additional work space. Removable one-piece work surface simplifies cleaning. Raised airflow grille maintains safety by preventing blockage. Optional UV lamp is located behind control panel away from line of sight. (Doesn't apply to 1.8 m / 6' models.) - Esco ISOCIDE antimicrobial coating on all painted surfaces minimizes contamination. Enhanced side-capture zones optimize containment. Work area on Esco 0.9 meter (3') cabinet is equivalent to work area offered on larger 1.2… plenum.