Stirrer A variety of stirrer & stirrer drives are available to use glass vessels as agitated reaction equipment.1. Stirrer material of construction: Glass, Stainless Steel or PTFE Lined. 2. Stirrer Design: Impeller stirrer with blades, Vortex stirrer, Propeller Stirrer & anchor Stirrer. 3. Stirring Drive: Non-flameproof or Flameproof stirrer drive, 192 RPM with Variable Frequency Drive. 4. Stirring Assembly: Stirring Assembly with bellow seal or with mechanical seal.