I use downtown, which became impassable for bikes this is it. My 45-minute bike almost daily are no longer viable without protection RADICAL !!! This filter is the one announced: FFABE1P3R D (acid gases), and you no longer feel poorly adjusted diesel. With this mask, one no longer feels any toxic breathing, you breathe well in spite cycling efforts, never dizzy or others. I recommend this product, the filte is highly efficient in any case, goal reached, my city is once again accessible by bicycle, I no longer hurt the lungs.