Included: (1) dust cap
The dust cap attaches to the end of the hub assembly at the center of the wheel. It protects the inside of the hub from dust and water and keeps grease inside the hub.
Metric measurements and specific to the Sportstar I trailer model.
Inside Diameter: 45.4mm
Overall Height: 27.5mm
Other related items: bearing buddies, hub cap, and grease cap.