This is commonly used for nuclease-sensitive assays. Labconco Purifier Class I Enclosures protect the user from agents that require Biosafety Level 1, 2 or 3 containment but no product protection. Exclusive features include: ergonomic air foil with aerodynamic Clean-Sweep airflow openings; upper dilution air supply; zone-perforated rear baffle; side-entry air foils; and upper containment sash foil. Other features include: nominal inflow velocity of 75 to 105 fpm; 99.99% efficient exhaust HEPA filter; variable speed built-in blower with vibration-isolated impeller and solid state control rated for 2 amps; intrinsically-safe, negative pressure design; Minihelic pressure gauge; low discharge volume and quiet operation