Abstract: A heat suppressor for a gas turbine engine is mounted on an aircraft by means separate from the engine mounts. A sleeve apparatus is needed to connect the exhaust duct of the engine to the suppressor duct for continuous flow of turbine gases. The sleeve apparatus is in the form of a bellows to absorb bending forces created by flexing of the air frame. This invention provides a unique connecting assembly to connect the bellows to the engine. The assembly consists of an annular socket fixed to the bellows and constructed to receive a radially extending flange on a connecting shroud fixed to the engine. The flange and socket are slidably engaged to allow twisting movement between the bellows and the engine, while the bellows allows relative displacement of the axes of the connecting passages.