Designed for aqua regia systems. This is a passive system and requires no pumps other other positive or negative air displacement apparatus.This is a passive unit that should be connected by hose to a sealed cylinder or other similar apparatus ( see Shor's beaker stoppers). Charged with treated activated charcoal (available separately). This fumes scrubber will scrub aqua regia fumes from up to 2 liters of aqua regia per run. A charge of treated activated charcoal typically will last for 5-7 refinings. If refining 5 liter aqua regia baths, two scrubbers, hooked in parallel, should be employed.