PTFE stirrer bearing with a hose connection for vacuum or inert gas source on a single neck flask. Grease-free design has only glass and PTFE in contact with the reaction, and can be used under moderate vacuum applications. Bearing consists of a threaded glass adapter having the listed inner joint size, a saddle O-Ring, a body Bushing with a compression and locking nut, and a precision PTFE inner bearing. Saddle O-Ring provides vacuum tight seal and is replaceable at a fraction of the cost of the entire bearing. Hose connection is 10mm at the largest serration.