Abstract: An adjustable fitting for directly connecting a wood burning insert for a masonry fireplace to a vent pipe positioned within a flue liner of the fireplace chimney is made up of an insert connector having first and second legs which are substantially perpendicular to one another. Thr first leg of the insert connector is vertically oriented when the fitting is in place and is sized to engage a flue gas outlet of a wide variety of wood burning inserts. A vent pipe connector completes the adjustable fitting and also has first and second legs which are substantially perpendicular to one another. The first leg of the vent pipe connector is vertically oriented when the fitting is in use and is sized to engage a lowermost end of the vent pipe.