3M Particle Filter D3138 P3R with Activated Carbon. Features: Protects against solid and liquid particles (use limit: 30 times the threshold limit) as well as organic and acidic gases and vapors below the threshold limit, and ozone and HF up to 10 times the threshold limit (HF up to a maximum of 30 ppm). Two dual airflow filters for low breathing resistance. Designed for use with the 3M HF-8 half mask series. Quick and secure Secure Click filter connection. Good visibility due to the slim filter design. For the 3M Secure Click HF-800(SD) half mask series. Filter class: P3R.