>> Search results for: R57B NSN Search Results National Stock Number (NSN) Description 4240-01-245-5914, 4240012455914 CARTRIDGE,RESPIRATOR,AIR FILTERI 5945-15-142-7928 , 5945151427928 RELE' 1 Related Inventory Search You can use this search box to continue searching. Search parameters can include any combination of characteristics, specifications, description, partial part numbers, NSN or other stocking number. Special characters are not needed and are automatically stripped before searching. Do you sell this part? Become part of our growing pool of certified suppliers. Send Information