Feature: 1. A TOTAL OF 48PCS: Including 16Pcs POM wheel, 16Pcs round column, 16Pcs eccentric spacer. Wonderful 3D printing accessories set for you 2. SMOOTH WITH LOW FRICTION: POM pulleys are strictly designed and tested to make them work smoothly and stably; silent design, low friction, and bearings are durable. Getting POM wheel will make your work even better 3. APPLICABLE MODELS: Provides good performance for all DIY 3D printers, such as for Creality CR10, for Ender 3, for Ender 5, for Anet A8, for E10, for Anycubic, for Anet series 3D printers, for Tevo Tarantula, CNC Router Hybrid, 8020 3030, etc. 4. NOT EASY TO RUST: Possess better performance than iron bearing wheels. The 3D printed wheel with rubber bearing is new development. Good surface without rust 5. HIGH ACCURACY AND FAST SPEED: These 3D printer wheels move smoothly, with low noise and high printing accuracy, which can improve the printing speed well 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 Wheel16 x Eccentric Spacer16 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.