Designed to providerespirator wearers with Grade-D quality air from a compressed air source.Meets OSHA 1910.134 criteria. Specifications: Filter change indicatorsare standard on all three stages, automatic drains in 1st and 2nd stage,0-160psi pressure gauge,adjustable pressure regulator, preset reliefvalve, visual flow meter and durable polycarbonate case that can be wallmounted. In-line Carbon Monoxide monitor with visual and audible alarm.