The pulleys are produced by high-precision automatic lathe machining, with machining error within 0.005mm. Smooth motion, high printing precision, low noise, can greatly improve the printing speed. Perfect 3D Printers: CR-10, CR-10S, Tevo Tarantula, CNC router hybrid, 8020 3030 and so on. This pulley bearing adopt of Motor grade bearings, rust resistant, wear resistant, excellent friction resistance and operate smoothly. Used 3D Printers, NC Engravers, Hot Wire Machines, Cutters, Camera Sliders, Plasma Cutters, Robotics, Furniture, And other DIY machine It is measured by professional inst ents and the advantages and characteristics of the pulley work. Smooth motion, low noise, high printing accuracy, and greatly improved printing speed. Colour: parent Material:Polycarbonate Package Contents: 20 x Polycarbonate Pulley Wheel Only the above package content, other products are not included. Note: Light shooting 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.