"I have used many dust masks. I must say this mask was comfortable. The soft fabric fitted easily to my face I had none of those leaky bits on my cheeks bones that let dust in. The valve is a must and makes it easy to wear.
There was none of the characteristics of dust getting up my nose either.
So well done 3M.
Why didnt I score it full marks, well here has to be room to improve and I have only worn it for 4 hours."