Bullard® Free-Air® pumps transfer ambient air from a breathable air source to a supplied-air respirator. The ambient air is filtered through an inlet filter and a Carbofine outlet filter before entering the respirator's air supply hose. No carbon monoxide, oil vapor or oil mist is produced; therefore, carbon monoxide monitors, high temperature alarms or airline filters are not required. No calibration necessary. Supplied-air respirators used with these pumps must be NIOSH approved to operate at 15 psi or less. One-Two Worker Pump Supplies air to 2 continuous-flow supplied-air half- or full-face mask respirators, or 1 continuous-flow supplied-air hood or helmet respirator. Open drip-proof motor drive for use in clean, dry areas. Airflow 10 cfm at 5 psig.