Full support in all directions As the name implies, Seldéns MDS (Multi-Directional Support) cars are supported in all directions, making sail handling simpler. A full batten always creates a side load on the cars, particularly when you release the halyard for taking a reef. Each car has side-load absorbing wheels that run against the guiding flanges in the luff groove. The interaction between the mast section and the MDS car deals with longitudinal loads, as well as side loads. This is the essence of the MDS concept. Since the cars need no external track, there is also less weight aloft. The MDS cars are easy to keep clean and are easy to install or remove from the luff groove. The MDS system is a suitable complement to the Seldén Single Line Reef boom. With such a combination on board, you have a simple and easily manoeuvred system for handling the mainsail in all weathers.