It is a "one-time mask", ie it should not be reused, is only intended for one person and should not be worn for more than 8 hours. The latter is relative, since adding the breathing valve with time and as a function of the intensity of the dust.
The mask is made of Zelstoff and has excellent wear properties. The feeling on the skin is thoroughly enjoyable. They can be attached quite securely with elastics. For more precise adjustment, there is a nose piece of plastic coated wire. This allows very precise adaptation, so that eyeglass wearers can work well and fog-free with the mask.
The valve is working properly. It comes with plenty of headroom, and there is no feeling of "shortness of breath". Only after adding the particulate filter, it is bad and you should replace the mask.
It is very useful to read the good manual. In addition, there's a video on Youtube, showing the functional and explains.
The mask is not very favorable. However, it also works much better as a cheaper competitor. Ultimately, everyone must decide for themselves, but dust is a tricky business and the treatment of the diseased lung is still difficult.
Conclusion: Very good dust mask is pleasant to wear. Recommended.
