looking in the Editor, there appear to be two versions of the APR [NATO] , listed as G_AirPurifyingRespirator_01_nofilter_F and G_AirPurifyingRespirator_F, so looks like two sepearate models, one with a filter, one without. The one without the filter connects to the Combination Unit Respirator and appears is the default Facewear used for the specialist. Changing the facewear, and relaunching the Virtual Arsenal, leads to only G_AirPurifyingRespirator_F being present