Sartolab® RF | BT vacuum filtration units are designed for research purposes, and therefore for filtering small volumes from 50 ml to 1 L. Sartolab® RF as a complete system includes a flask to receive the filtrate to the filtration funnel. Sartolab® BT is a filter at the top of the bottle (filter funnel) without a flask, which allows users to use their own flasks and / or expand the filtration capacity, depending on the particle load of the filtered liquid, by filling more than one flask.