Slide device and camper or caravan with extensible side parts

The unit has a fixed rail with support rollers on the front end, and a pull-out rail with running rollers on the rear end. The pull-out rail (2) is longer than the fixed rail (1) by 20%, pref. 30%, and extends over its rear end when in nested position. The running rollers (7,8) of the pull-out rail are located outside the running surfaces of the fixed rail, and the pull-out rail is supported on a bearing unit (6) on the rear section of the fixed rail. The sliding unit is for the support of body sections, which can be pulled out of the sides of caravans etc.