During Soviet times, almost every home had at least one gas mask issued by school, university or work. Now, if necessary, a gas mask can be bought at a specialized store.
It is necessary
Before buying or ordering a gas mask through a reliable website, you need to find out which size is right for you. There are several ways to determine the size of a gas mask, depending on the measurement method as well as the brand.
If you are going to purchase a gas mask with a helmet-mask (GP-5, RSh-4, PMG, PBF), you can find out your size in two ways.
Take a centimeter and measure the length of the closed line that should go across the crown of your head, chin, and cheeks. Then measure the length of the line connecting the auricles and passing through the brow ridges. Add up the results of the first and second measurements. Round the total to 0, 5, or one.
Find out your size. So, if in total you got up to 92 cm, then you should purchase a gas mask of size "0", from 92 to 95, 5 cm - "1", from 95, 5 to 99 cm - "2", from 99 to 102, 5 cm - "3", more than 102, 5 - "4".
With the second method of measuring the head for a gas mask of one of these brands, it will be enough for you to know the length of the line passing through the crown, chin and cheeks. If the length is up to 63.5 cm, then this will correspond to size "0", from 63.5 to 65.5 cm inclusive - "1", from 66 to 68 cm - "2", from 68.5 to 70.5 - "3", and more than 71 cm - "4".
If you plan to purchase a gas mask with elastic bands adjustable from behind (GP-7, PMK), then you will have to make measurements of a slightly different nature. Take a centimeter and measure the horizontal head circumference (in much the same way as when choosing a headdress).
If the circumference is up to 56 cm, then it means that you should buy a gas mask of these brands, having the size "1", from 56 to 60 cm - "2", more than 60 cm - "3".
Before finally making sure of the correctness of your choice, try on a gas mask of your chosen brand. Do not forget to remove your hair before trying it so that it does not break its tightness.