It is an Upper Track for Sliding Door in showcase system. When there is needed to install sliding doors, E400 can be used as a track. E400 is inserted into the groove of extrusions and works with E401 to make the door slide. There are two tracks for two 4mm door panels. Its size is 16*18mm. Its max length is 5m. It weighs 0.140kg per meter. If you have any other requirements, LingTong will meet your needs. It is made of plastic. The products of LingTong are green and environmentally friendly. If there are some relative needs, LingTong will provide the best service for you in exhibition construction