The BREATHER BOX is a portable Grade-D filtration system designed to provide breathing air for a specific number of workers. The system filters incoming air from a compressor to provide respirator users with Grade-D quality air and monitors for CO and/or Oxygen. All Breather Boxes are designed to be used in the upright and closed position to prevent internal contamination. The standard carbon monoxide (CO) airline monitor operates on disposable 9-volt batteries, 8-16 volt DC, or 115 VAC for continuous air monitoring. An external audible alarm and light signals the workers of high CO content. A remote alarm jack is provided on all models except for Model BB15-CO. Point-of-Attachment (POA) boxes can extend respirator usage beyond 300 feet.