Secure Click D3135 particulate filter, protection level P3 R, pack of 10 pairs, for half mask HF-800. Product type = replaceable filters for half/full masks. Protection class = P3 R. For protection from solid and liquid particulate matter (limit for use: 30 times the threshold) Two dual air flow filters for low breathing resistance levels. For use with the 3M Secure Click HF-800 (SD) half mask series. 3M Secure Click D3135 particulate filter, P3 R, for protection from solid and liquid particulate matter (limit for use: 30 times the threshold) For use with Secure Click HF-800 (SD) half mask series. The 3M Secure Click D3135 particulate filter, P3 R, is a lightweight filter that combines protection and comfort. Used in pairs, our filters feature low breathing resistance levels and good balance with an optimal field of vision. They click into place on the 3M Secure Click HF-800 (SD) half mask series quickly and easily.