For use with Flask Head 9443. By using precision bore tubing throughout the length of the bearing, a stirrer is produced that will hold to within 1mm of vacuum and withstand pressures in the flask up to 300mm. The 9532 Agitator, used with this bearing actually develops a negative pressure of 230mm water at operation speeds. The side opening on the bearing is used to add gases through the hollow rod stirrer as listed under 9532. 10 mm I.D.