Abstract: A travel trailer having a rear end wall with an extendable or slide-out room. The vehicle also has a floor and an opening in said rear end wall, such that said slide-out room is fitted in said opening. The vehicle includes an upper mechanism and a lower mechanism for supporting the slide-out room for movement between a retracted position within said vehicle spaced above said floor and an extended position projecting rearwardly of said rear end wall. A ceiling is attached to and perpendicular to the rear end wall wherein the upper mechanism includes a guide rail mounted to the ceiling and a hanger attached to the slide-out room for moving within the guide rail. The guide rail has a generally C-shaped cross sectional configuration so as to provide a slot which extends longitudinally along the rail such that the hanger extends through the slot, the hanger having rollers supported within the guide rail to facilitate movement therein.