Review on 4WDKING Connector Airpro Electrical Purifying by Dale Toth

You can use it on any mask and it increases your safety. It also makes breathing easier in hot weather. I have severe breathing problems and tolerate this mask without any problems. The filter does not need to be replaced every 500 hours and costs less than $10. In addition, masks with a safety valve cannot be worn in many places. This is an acceptable device for all the hospitals I've been to lately and no one has ever refused me entry with it. You breathe in and out the filtered air like you normally do with the mask you're using.