For the filtration of aqueous and aggressive solutions. The PES membrane filters have excellent flow speeds and are connected to a high filterable volume. Biologic and pharmaceutic solutions can be filtered in the wide pH-range of pH 2 to 12 because of their low protein adsorption. Furthermore, the membranes are very well suitable for samples of the environmental sector. The filters with 0.1 µm are used for the ultracleaning of solutions, e. g. in case of nephelometry.