Features: Make of metal and rubber, ensuring perfectly strength and reliability. Ball bearing design, smoothe driving. Easy to Use. 0-5CM length can be retracted to reduce shock and pressure, and can also be used on uneven ground. Enjoy smooth and efficient gate maneuverability with our 360-degree rotating casters, allowing easily movement in any direction. Suitable for many ground surfaces, including grass, cement, cloth roads, and floor tiles. Specifications: Materials: Metal and Rubber Style: 4inch black/4inch silvere/5inch black/5inch silver Tire diameter: about 10cm/3.94inch Wheel width: about 2.4cm/0.94inch Package Includes: 1pc Garden Gate Wheel note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to difference between different monitors, the picture may not reflect the actual color.