3M filter #5N11 for use with 3M respirator models #5000, 6000 and 7000 series respirators. N95 Pre filters help prolonge the life of the respirator by trapping dust, mists and particles. N95 filter approved for non oily environments. 10 filters per package. These prefilters must be used with 3M #501 filter retainer, which is sold separately.