Features 48 Pieces in Total: Including 16 POM wheels, 16 cylinders, 16 eccentric spacers. Exquisite 3D printed accessories set for you, wheels have good physical, mechanical and chemical properties, especially good wear resistance. Smooth and Low Friction: POM pulleys are rigorously designed and tested to make them work smoothly and stably; silent design, low friction, and durable bearings. Getting POM wheels will make your work even better. 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 Rust: Has better performance than iron bearing wheels. 3D printed wheels with rubber bearings are a new development. Good surface does not rust. High Precision and Speed: These 3D printer wheels move smoothly, with low noise and high printing accuracy, which can improve the printing speed well. Widely used in four-wheel alignment, line rails, pulleys. Specification: Item Type: POM Pulley Wheel Set Product Material: Accurate steel, rubber Pulley Inner Diameter: 5mm / 0.2in Pulley Bearing Outer Diameter: Approx. 8mm / 0.31in Pulley Height: Approx. 9mm / 0.35in Chute: Approx. 6mm / 0.24in Pulley Outer Diameter: Approx. 15mm / 0.59in Eccentric Spacer and Round Column Inner Diameter: Approx. 5mm / 0.2in Eccentric Spacer and Round Column Height: Approx. 8mm / 0.31in Product Use: For 3D printers Package List: 16 x POM Wheel 16 x Eccentric Spacer 16 x Round Column Note: Note that there is a movable copper ring between the bearings. Ring movement is normal, otherwise the bearing cannot turn. It's not a quality issue. Package List 16 x POM Wheel 16 x Eccentric Spacer 16 x Round Column