The supplied 4 Layer Face Mask consist of 4 layers starting from the outermost layer which is the water-resistant layer, then comes the second layer, which is a filter for bacteria and virus, then comes the third layer which is a filter for the ultraviolet rays, etc. And then comes the fourth layer which is again a water-absorbent layer. A mask with layers will stop more droplets from getting through the mask or escaping from it. The 4 Layer Face Mask is very effective.