General description U-track wheels are designed for various applications, including sliding doors, mechanical trolleys, and mobile workbenches. This pack includes 4 pieces of U-shaped track casters that provide smooth sliding performance. Technical specifications Material: 45# high strength steel with colorful zinc plating Load capacity: 204.1 kg Dimensions: 5.6 cm (L) x 3.2 cm (W) x 4.1 cm (H) Wheel diameter: 3 cm Wheel width: 2.5 cm U-notch width: 1.5 cm U-groove depth: 0.8 cm Built-in 2 ball bearings for enhanced sliding performance Compatible with 1.7 cm round tube as a track Other information Package includes 4 pieces of U-track wheels