Features LOW FRICTION: POM pulleys are strictly designed and tested to work smoothly and stably; Silent design, low friction and durable bearings. Getting the POM wheel will make your job even better HIGH PRECISION AND FAST SPEED - These 3D printer wheels move smoothly, with low noise and high printing accuracy, which can improve the printing speed well APPLICABLE MODELS: Provides good performance for all DIY 3D printers, such as Creality CR10, Ender 3, Ender 5, Anet A8, E10, Anycubic, Anet series 3D printers, Tevo Tarantula, CNC Router Hybrid, 8020 3030, etc NOT EASY TO OXIDATE: It has better performance than iron bearing wheels. 3D printed wheel with rubber bearing is a new development. Good surfaces without rust. A TOTAL OF 48 PIECES: includes 16 piece POM wheel, 16 piece round column, 16 piece eccentric spacer. Wonderful 3D Printing Accessories Set for You Specification: Item Type: POM Pulley Wheel Set Product material: precise steel, rubber Pulley Inner Diameter: 5mm/0.2 in Pulley bearing outer diameter: approx. 10mm/0.39 inches Pulley height: approx. 9mm/0.35" Duct: approx. 6mm/0.24" Pulley outer diameter: approx. 15mm/0.59 inches Eccentric spacer and round column Inner diameter: approx. 5mm/0.2 inch Eccentric spacer and round column height: approx. 8mm/0.31" Product Use: For 3D printers Package List: 16 wheels POM 16 x Eccentric spacer 16 x Round Column Note: Please note that there is a moving copper ring between the bearings. The movement of the ring is normal, otherwise the bearing cannot rotate. It's not a quality problem. Package List 16 x POM Wheel 16 x Eccentric Spacer 16 x Round Column