The 3M ™ 9925 welding filter half mask against welding gases provides light, effective, comfortable and hygienic respiratory protection against dust, aerosols and metal fumes. It provides protection against ozone and welding fumes, as well as relief from annoying odors. Marking D on these filter half masks indicates compliance with the special requirements of the dolomite dust clogging dust filter filter (FFP), which can be used for more than one shift.