Claisen adapter

The Claisen adaptor is a multi-purpose item of standard taper glassware. It is used in situations which require more than one outlet from a round-bottom flask. For instance, in a reflux of a reaction mixture, sometimes it is necessary to condense the rising vapors and add reactants to the mixture at the same time. In this situation, one of the upper joints of the Claisen adaptor would go to a condenser and one to a dropping or separatory funnel. [orgchem.colorado.edu/Technique/Equipment/Rxnglass/Claisen.html]