of heater core extension tubes having different geometries application_number US 59454806 A description the following detailed description and appended drawings describe and illustrate various exemplary embodiments of the invention the description and drawings serve to enable one skilled in the art to make and use the invention and are not intended to limit the scope of the invention in any manner fig1 shows a connector tube 10 in accordance with an embodiment of the invention the connector tube 10 is typically formed from aluminum however other materials can be used to form the connector tube 10 as desired the connector tube 10 includes a first end 12 a second end 14 and an intermediate portion 16 disposed between the first end 12 and the second end 14 the first end 12 of the connector tube 10 is substantially circular in cross section and is adapted to receive a male end 18 of an extension tube 20 a first flared portion 22 is formed on the first end 12 the first flared portion 22 is flared radially outwardly from the first end 12 a distal end 24 of the first flared portion 22 is adapted to abut a radially outwardly extending lip 26 formed on the extension.