Cost effective ambient air pumps protect workers in supplied air environments. Special design supplies clean, breathable air to NIOSH approved respirators. Pumps are portable and oil-less for convenience. Produce no carbon monoxide, oil vapor, or oil mist, thus eliminating the need for carbon monoxide monitoring and alarm systems. Easy to maintain - only 1 moving part. Rotary vane pumps use 4 carbon vanes that last for 5,000 to 15,000 hours of continuous running.