A bike trailer is a wheeled attachment designed to be pulled behind a bicycle. It is commonly used for transporting cargo, children, or pets, making it a versatile accessory for cyclists. Bike trailers come in various sizes and styles, including those specifically designed for carrying groceries or outdoor gear. These trailers typically feature a sturdy frame, a hitch that connects to the bike, and safety features like reflectors and safety straps. Many models are foldable for easy storage and transport. Popular brands include Burley and Chariot, which offer options for different needs and preferences.