A Büchner flask, also known as a vacuum flask, filter flask, suction flask, side-arm flask or Kitasato flask, is a thick-walled Erlenmeyer flask with a short glass tube and hose barb protruding about an inch from its neck. The short tube and hose barb effectively act as an adapter over which the end of a thick-walled flexible hose (tubing) can be fitted to form a connection to the flask. The other end of the hose can be connected to source of vacuum. It can also be used as a vaccum trap to stop liquids being carried over from vaccum pump.
