QCCAN 21PCS/Set GT2 Timing Belt Pulley Include 8pcs Mix Timing Belt 6 Mm Width21 Pieces 3D printer accessories include 8pcs timing belt 6 mm width, 8pcs 20 teeth 6mm bore belt pulley wheel, 4 tensioner spring torsion with 1pcs allen wrench for 3D printerTiming belt:Synchronous belt pulleys:Material: Aluminum Alloy, Surface oxidation treatment, durable, fine workmanship and high transmission accuracy; bore synchronous wheel in contact with the belt can minimize the chance of belt slipping.Locking spring:It is made of carbon steel, it has corrosion resistance and high surface strength, with spring, you can add the appropriate tension required and make printing more poundsProductdimensions2.8 x 1.1 x 4.2 inchesMaterialCarbon SteelPartnumberQC19000Visit our store for more great deals!Thank you!