The stirrer unit is made entirely of PTFE. A stainless steel core provides the required hold in the clamping ring of the stirrer. The stirrer unit is firmly anchored to the shaft: it is not loosened by continued turning of the medium after the stirrer has been turned off. Since the materials to be turned only have contact with PTFE, the stirrer shafts are virtually resistant to chemicals and allow high application temperatures. The dimensions of the stirrer shafts match the (KPG) glass stirrer shafts and are therefore interchangeable at any time. With tapered collet, for easier clamping of stirrer shafts.