Alternative to the face masks N5400 class 1 & N5400 class 2. In combination with this full face mask, the following filters can be used: RD40 Gas Filter A2 (1785010), RD40 Combination Filter A2P3 (1783010), RD40 Combination Filter A2B2P3 (1783040), RD40 Combination Filter A2B2E2K2P3 (1784000), RD40 Dust Filter P3 (1786000).