The timing belt is made of high-quality Material, which is durable and flexible. Designed for linear motion, high positioning accuracy. The round tooth profile ensures a smooth fit of the belt teeth. Most 3D printers are popular. The timing pulley is made of high-quality Material, which is well-processed and has a smooth surface. The timing pulley has 20 teeth in contact with the belt, minimizing the risk of belt slippage. The timing belt idler pulley is made of high-quality Material with high hardness and anodized surface treatment, which is effectively waterproof, rust-proof, corrosion-resistant, and more beautiful and durable. The locking spring is made of high-quality Material, which has corrosion resistance and high surface strength, using the spring can increase the proper tension and make the printing more precise. mounting module that mounts to the open buckle on 2GT belts (and some other models); keeps secure without loosening. Material: aluminum+rubber colour: black+silver Package Contents: 1 x 5M GT2 Timing Belt 10mm Width 6 x 20 Teeth 5mm Bore Timing Pulley Wheel 4 x 20 Tooth Bore 5mm Idler 4 x Tensioner Spring Torsion Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.