Features: When the current passes through the coil, a magnetic field is generated around the coil. This additional magnetic field can generate an external force on the upper permanent magnet or press or suction. By adjusting the magnitude and direction of the current flowing through the coil, the force can be adjusted to generate a stable magnetic suspension. Made of material, making it . Magnetic levitation coil only, other accessories shown in the picture are not included. Specification:Material: Metal Color: Brown Outer Diameter: app.19mm/0.75in Height: app.12mm/0.47in Quantity: 5pcsNote:No retail package Transition: 1cm=10mm=0.39inch Please allow 1-3mm error due to manual measurement. Pls make sure you don't mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package Included: 5pcs x Magnetic Levitation Coil