The package includes: 2 bicycle trailer couplers + 2 connecting pins. Lightweight, compact, and portable. You can easily store them in your bag and take them with you. Material: The bicycle trailer coupler is forged from high-quality steel, making it sturdy and durable, with good corrosion resistance and no damage. Safety: Our 135-degree bicycle trailer coupler includes connecting pins that are difficult to open after installation to ensure the safety of children or pets. Easy to install: After installing the bicycle trailer coupler, simply ensure the locking pin does not move when tightening and is securely locked. Scope of application: Our bicycle trailer couplers are suitable for quick-release axles and solid axles up to 12.2 mm/0.5 inches, and are compatible with conventional bicycles and models with disc brakes and full suspension. They fit most bicycles, strollers, carriers, vans, etc.