Ready-to-use sterile filter units ideal for microbiological control of various kinds. Made up of a base with a filter membrane, a cellulose absorbent pad underneath, a 100 ml graduated funnel and a lid with a magnifier. White non-welded membrane. Single use only. After filtering, its base together with the lid can be used as a Petri dish. Sterilized by gamma radiation and individually packed in an easy-open polyethylene bag