Tested and certified by the National Institute for Occupational Safety and Health (NIOSH), a research agency that is part of the Centers for Disease Control and Prevention.

• Standards: GB 2626-2006 EN 149
• No valve
• Inner layer: 30g non-woven fabric
• Filter layer: 40g melt-blown non-woven combined fabric
• Third layer: 50g hot air cotton fabric
• Outer layer: 50g non-woven fabric