A lug wrench is a tool used to loosen or tighten the lug nuts on a vehicle's wheels. It typically has a long handle for leverage and may feature a cross shape or a socket design to fit various sizes of lug nuts. This tool is essential for changing a flat tire or performing maintenance on a vehicle. Most lug wrenches are made of durable materials like steel to withstand the force needed to turn stubborn nuts. Some vehicles come with a standard lug wrench as part of their emergency kit, often stored in the trunk alongside a spare tire and a jack.