Usage Tips:Durable Material: This Bike Trailer Hitch is made of high quality stainless steel, strong and durable. Features: Bicycle cup mount bike trailer hitch, easy to use, a necessary bicycle tool, compact, lightweight, suitable for carrying around. Easy to Use: The trailer hitch is easy to use, slide the ball into the cup mount, and lock the pin in place. Bicycle Tool: Enjoy the joy and excitement of transporting your kids or pets around with your bikes. you can spend a wonderful family time! Size: The mount hitch cup size is 3.9cmx3.3cmx6.5cm/1.54inchx1.30inchx2.56inch. Specification: Material: Stainless Steel Size Chart: 3.9cmx3.3cmx6.5cm/1.54inchx1.30inchx2.56inch Package Includes: 1 Bike Trailer Hitch Note: Please allow slightly errors due to manual measurement and different monitors.