A bike trailer is a wheeled device that attaches to the back of a bicycle, allowing for the transport of cargo, children, or pets. They come in various sizes and designs, including single and double configurations, and can be used for recreational or practical purposes. Bike trailers are typically lightweight and designed for easy maneuverability. Many bike trailers feature safety harnesses, weather protection, and storage compartments. They are popular among families and outdoor enthusiasts, providing a convenient way to carry items without overloading the bike itself. Some models are specifically designed for children or dogs, ensuring a safe and comfortable ride.