Allegro Industries 9920 Constant Flow Airline Respirator Half Mask SAR System. The Allegro Industries 9920 Constant Flow Airline Respirator is a NIOSH-approved supplied-air respirator (SAR) system designed to provide dependable respiratory protection in general industrial applications. This complete system features a comfortable half-mask respirator with a silicone rubber face seal, breathing tube, low-pressure flow adapter, and support belt for reliable all-day performance. Designed for use with ambient air pumps, the Allegro 9920 delivers a constant flow of breathable air while maintaining comfort and mobility. The universal-size half mask features an adjustable headband suspension for a secure fit, making it ideal for painting, manufacturing, maintenance, sanding, and other environments requiring supplied-air respiratory protection. Genuine Allegro Industries 9920. NIOSH-approved constant flow supplied-air respirator (SAR). Comfortable half-mask with soft silicone rubber face seal. Universal size with adjustable headband suspension. Designed for use with ambient air pumps. Includes breathing tube, facepiece, support belt, and low-pressure flow adapter. OBAC fittings and couplers. Ideal for industrial, maintenance, painting, and general-purpose applications. Type: Constant Flow Airline Respirator. System Type: Supplied Air Respirator (SAR). Headgear Type: Half Mask. Headgear Material: Silicone Rubber Seal & Rubber Suspension. Air Source: Ambient Air Pump. Operating Pressure: 12 psi. Country of Origin: USA. 1 × Half Mask Respirator. 1 × Breathing Tube. 1 × Low Pressure Flow Adapter. 1 × Support Belt.