Airtrim is a heat/moisture exchanger which recovers the heat and moisture from exhaled air. The filter heats the air you breathe in, protecting your air passages from the cold. Airtrim Standard comes packed with two different filters. The filter inside the mask is a sports filter, suitable for winter training.
The extra filter in the package is an asthma filter, suitable for people with asthma or angina who suffer from the cold. Because it conserves heat more effectively, it can be used to ward off hypothermia in the event of an accident.
During continuous use the filter gets very damp, and you should clear it regularly by blowing vigorously through the mask. Avoid touching the wet filter as it tears easily. Allow the mask and filter to air dry.

Always bring along spare filters on long training sessions and mountain trips. Spare filters must be kept dry.
 
Sleeping with Airtrim
When your throat feels dry and raw, Airtrim can give relief indoors as well as out.
Use the asthma filter for this, as it recovers heat and moisture most efficiently. The warm, moist air relieves congestion and eases an irritating cough. Try adding a drop of mouthwash, peppermint oil or basil oil to the inside surface of the filter..
 
Racing filters
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The racing filters were developed especially for sportspersons who drive themselves hard and don't need a great deal of warmth. They provide varying levels of heat recovery and have lower breathing resistance than the original filter..