This version of the W65-2 is a standard filter self-rescuer, proving you up to 120 minutes in an escape situation. It’s a one-time use device and will offer protection from carbon monoxide and other toxic gases caused by underground mine fires or explosions. One of the great advantages of using the W65-2 is how quickly it can be donned and used. It’s lightweight and small design also makes it comfortable to wear and use. The integrated CO filter is an oxidation catalyst, which works to convert CO to carbon dioxide. The integral heat exchanger will reduce the temperature of inhalation air to a more comfortable level. Any expired air is passed through a heat exchanged and a spring-loaded exhalation valve and into the ambient air.