Compact design laboratory flask stirrer featuring integrated drive and stirring seal allowing direct installation of flask and stirring in a vacuum and sealed state. Designed with manual type rotation speed. Wide range rotation speed of 50-1000 rpm. Maintenance free and superior DC brushless motor. Belt drive transmission minimizes noise and vibration. Capable of vacuuming up to 399.9Pa without impairing rotation efficiency. Directly attachable to a three-neck flask 24/40, 29/42 optional. Variety of stirring shafts and blades available to handle small to large volume samples. Fluorine rubber seal as standard for shaft seal, superior chemical resistant Teflon®rubber seal available as option. At the flask joint, FKM o-ring is used as standard, superior chemical resistant Kalrez® o-ring available as option. Equipped with 24/40 rotary joint, 29/42 optional. Operating speed range 50-1000 rpm.