DescriptionMade of material, these wheels are durable and sturdy. There are total 6 pieces of wheels in one set, which you may use for many projects. They are normally used for 3D printers, CNC machines and many other machines, lightweight design, exquisite appearance, and easy to use.Feature- Color: Assorted color. - Material: Plastic. - Size: 2.40X2.40X1.10cm/0.94X0.94X0.43 inch. - The plastic roller bearing is a passive round model pulley for 3D printer. - This 3D printer pulley is widely used for wheel alignment, wire and belt. - The outside of the wheel is made of material with good physical, mechanical and chemical properties. - These pulley bearings have motor ball bearings, resistant to rust, wear, excellent rub resistance and work smoothly. - Fine workmanship and creative appearance ensure its popularity and practicality.