Solid industrial-grade steel, high strength, wear resistance and rust resistance; Surface: satin black. [Invisible floor guide]: Fix to the wall with screws and create a groove in the door. Adaptation of the door covering; There is no need to drill holes in the floor. [Adjustable]: Wide range of applications, the thickness of the doors can be adjusted from 14 to 40 mm. Place the sliding door in the middle of the guide rail to avoid the appearance of cracks. Package includes]: 1 floor rail