Useful extension to the existing range of Bola stirrer shafts. The additional blades can optionally be fixed in your preferred position on every stirrer shaft with diameter 8,10 or 16 mm (a flat spanner is included). The stirrer blades are entirely made of PTFE, the mounting devices are made of a special PTFE-compound. A high chemical and thermical (-200 to +250 °C) resistance is assured. This "building block system" allows the user to define a stirrer of their own special requirements.