Quantity: One pieceColor: BlackProduct size: Refer to the pictureMaterial: Heavy duty carbon steel body and nylon rollers for smooth and quiet sliding;Easy installation: No grooves for doors and no drilling for floorsSize: The wheel diameter is 37mm; Applicable door thickness: 2.5 cm - 5 cm; Practical and innovative design: The invisible swivel wheels on the vertical side not only make sliding easierThe outer ring of the double pulley is made of high-quality silicone, which is extremely soft and leaves the door free of scratches. The double pulley is filled with sturdy nylon material, which is firmer and not easy to deformThe lower seat of the double pulley is made of hard carbon steel, which does not corrode and firmly fixes the door. The 5 mm base is suitable for doors with a height of 7 mm above the ground and less than 30 mmThe small wheel on the side has a thickness of about 13 mm. It is suitable for doors whose door is about 15 mm from the wall. Doors with a thickness of 25 - 45 mm can be used.