Product Specification: Material: Made of high quality aluminum alloy. Tooth Number: 20&60T Bore Diameter: 5mm/0.2inch Timing Belt Length: 200mm/7.9inch Timing Belt Width: 6mm/0.24inch Color: Silver Application: Widely used in milling machines, gear shaping machines, drilling machines, milling machines or other machine transmission occasions. Package Contents: 2pcs GT2 60 Teeth 5mm Bore Synchronous Wheel 2pcs GT2 20 Teeth 5mm Bore Synchronous Wheel 2pcs Length 200mm Width 6mm Belt 4pcs M4 Screws 1pcs M4 Allen Key.