Reusable combined filter 725 abek2hgp3 r d. designed to protect against chemical gases and vapors (types a, b, e, k), mercury (hg), and solid and liquid particles (p3). composed of two stages: chemical filter in a bell-shaped plastic casing for optimized airflow and a truncated conical p3 particulate filter assembled over the gas filter. 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 din en 148-1 connection. standard en 14387:2004+a1:2008