Features: Made of metal and rubber, ensuring perfect strength and reliability. Ball bearing design, smooth 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 easy 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 silver / 5inch black / 5inch silver Tire diameter: about 10cm / 3.94inch Wheel width: about 2.4cm / 0.94inch Package Includes: 1 pc 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.