3M 837730 Adflo Belt Unit Kit Features Adflo Respiratory Device and self-adjusting Respiratory Tube QRS, Respiratory Tube adapter, airflow indicator, pre-filter, spark arrester, particulate filter, battery, strap, and charger. With its intelligent, compact design, the award-winning Adflo electric air respiratory system is specifically designed to meet welding needs. With the correct filter type, the Adflo respiratory device provides effective protection against both particles and gases; it is an all-in-one system. The airflow is always at a stable nominal 170 liters/min, independent of battery charge or particulate filter load. In hot, humid tasks, you can increase the airflow up to 200 liters/min by pressing the ON button a second time. The lightweight Lithium-ion battery fully charges in 4.5 hours and has an 8-hour working time.