In metal and plastic, with wheels. It slides easily and is very sturdy. Suitable for cupboards, cupboards, bookcases and other office furniture. < p>Note: the diameter of each wheel is 14.5mm. Before buying, please make sure it matches your furniture size Features: Made of metal and plastic, with wheels. It slides easily and is very sturdy. Suitable for cupboards, cupboards, bookcases and other office furniture. < p>Note: the diameter of each wheel is 14.5mm. Before buying, please make sure it matches your furniture size. Details: Material: metal and plastic. Color: Silver / White Dimensions: Central thickness: 5.5 mm External width: 17.5mm Suitable for track height: 15-20 MM Inner width of sidewalk soft channel: 18-23MM Track center width: 6-7.9MM Wheel diameter: 14.5 mm. Package content: A set of 10 wheels. Note: the data is all manual measurement, please allow 1 - 3cm error, due to the light and display difference, there will be some color difference, depending on the physical object received Delivery Quantity: (according to the main image)