Abstract: A vehicle having an expandable slide-out body is provided. The slide-out body is movable relative to the vehicle by a slide-out apparatus. The slide-out apparatus has first and second rails, and first and second synchronization members. The first rail is attached to the vehicle and defines a first longitudinally-extending compartment. The second rail also has a second longitudinally-extending compartment. The second rail is attached to the slide-out body, and is disposed within and movable relative to the first longitudinally-extending compartment. The first synchronization member is attached to the second rail. The second synchronization member is located inside the second longitudinally-extending compartment and is engagable with the first synchronization member.