This NORTH 7904 Mouth Bit Escape Respirator for Ammonia Methylamine is a disposable air purifying respirator designed for emergency escape from Ammonia contaminated atmospheres. NORTH 7902 Mouth Bit Escape Respirators for Acid Gas contaminated atmospheres are also available and sold separately. 7904 Respirators sold each. 10 Respirators per case.
See TnA Safety, Webster, NY on MacRae's Blue Book