Abstract: The present invention relates to a device at rails for exhaust extraction devices, which are adapted for removal of exhausts from vehicles. The rail (2) consists of several rail members (5) which are put together or assembled by means of coupling elements (6). The coupling elements (6) are wedge-shaped and the shape of spaces (9) in rail members (5) for the coupling elements (6) corresponds with the wedge-shape of said coupling elements (6). Mounting means (10) are provided for downward movement (arrow A) relative to the rail members (5) and thereby, for pulling the coupling elements (6) upwards (arrow D) relative to said rail members (5) such that said coupling elements (6) and rail members (5) are secured by wedge to each other.