Product Description Asttar Underground mining filtered self-rescuer ZL60 ZL60 is a protective device for personal breathing system, the toxic carbon monoxide(CO) in air oxidizes into nontoxic carbon dioxide(CO2) through chemical reaction under normal temperature. It applies to the environment where the concentration of oxygen(O2) is not less than 18% and carbon monoxide(CO) not more than 1.5%, for the use of rescue teams in the event of an underground emergency. Specification