3M filter ventilation unit with 2 optional airflow options (185 l/min and 205 l/min) offering more comfort for the user; use is simple and versatile; highly effective filter captures hazardous dust, mist, and smoke; light and balanced design for greater user comfort; the intelligent lithium-ion battery charges quickly and is equipped with a useful charge indicator; low airflow or low battery status is signaled as well as battery charge; it also includes a load status indicator/particle filter and an airflow indicator.