Check the listing for details. 40mm NATO Gas Msk to 3M Respirator Filter Adapter SGE 150 400 NBC CBRN. Condition: New. Listed at 19.99 USD. Measure the depth of the threaded hole on your mask from the base to the gasket. If it is deeper than 1/2", please contact us for gasket shims. Adapts gas masks and respirators with 40mm NATO threading such as SGE 150/400 to accept 3M filters. 2-piece design allows for the filter to be able to be set in different positions so that the rectangular, non-round 3M filters can be used as wellIncludes gasket kitMeasure the depth of the threaded hole on your mask from the base to the gasket. If it is deeper than 1/2", please contact us for gasket shims. Adapts gas masks and respirators with 40mm NATO threading such as SGE 150/400 to accept 3M filters. 2-piece design allows for the filter to be able to be set in different positions so that the rectangular, non-round 3M filters can be used as wellIncludes gasket kit