Abstract: A method and apparatus for readily connecting a main component of a forced air heating and/or cooling system to a branch component so that the connection is airtight. An elongated tubular member has an enlarged circumferential face generally perpendicular to the direction of elongation of the tubular member formed at one end of the member, with a gasket attached to that face, glue on the exterior of the gasket, and a piece of release paper over the glue. The passageway through the tubular member is matched up with an opening in the heating system main component so that the gasket surrounds the opening in the main component, and the gasket is then pushed into the sealing relationship with the main component, the glue on the gasket face joining the tubular member and main component together. Then fasteners are passed through openings formed in the tubular member and gaskets so that the fastening members operatively engage both the tubular member and the main component and securely hold them together.