Big D Style POM Pulley Wheels with Bearings Gear for 3D Printer * The pulleys are produced by high-precision automatic lathe machining, with machining error within 0.005mm. * Advantages: Smooth motion, high printing precision, low noise, can greatly improve the printing speed. * Perfect For 3D Printers: CR-10, CR-10S, Tevo Tarantula, CNC router hybrid, 8020 3030 and so on. * Size: Outer Diameter – 0.94in/23.89mm; Bore Diameter – 0.19in/5mm; Height – 0.4in/10.23mm.