Reusable combined filter 725 abek2p3 r d (class 2 and 3). designed to protect against chemical gases, vapors, and solid and liquid particles (types a, b, e, k, and p3). composed of two stages: a chemical filter in a bell-shaped abs casing for optimized airflow and a truncated conical p3 particulate filter assembled via ultrasonic welding. featuring r marking (reusable filter) and d marking (dolomite test). features a standard en 148-1 (rd40) thread connection, compatible with full face masks of models 731, 731-c, 741, and equipment with normalized en 148-1 connection. standard en 14387:2021