Brand:SUYA Material:High grade carbon steel Finish:Matte Black Package included: Carbon Steel Tracks;Bearing Pulley; Limiter;Anti-jumper;Floor Guide; Door stopper;Track Spacer;Install Screws Product Features: (1)It was constructed of heavy duty steel and black lacquer finished surface which is waterproof and rust resistance. (2)There are 2 doorstops on the track ends prevent the pulley from rolling off; Doorstops can be located freely along the track;Upgraded Nylon Hanger makes it more silent. (3)It has GCR15 high precision bearing steel, we have passed the test and when it is closed 120000 times; (4)All the accessories are included,no need to break the wall and install a door frame to open and shut doors. (5)Professional instruction and customer service team help you solve all installation problems in time.If you have any problem during installation,Just feel free to contact us. Installation Precautions: 1.Above the door opening, a load-bearing wall must be ensured, and cement and red brick walls can be directly installed; if it is a non-load-bearing wall such as foam or hollow brick, wooden blocks need to be installed. 2.The distance from the top of the door opening to the ceiling should be greater than 16 cm + the width of the door cover. 3.The installed wall must be on the same horizontal plane, and the left and right sides must have a wall that is about as wide as the door opening, so that it can be pushed away.