A fuel tank trailer is a non-powered, towed vehicle designed for the bulk transportation of gasoline, diesel, aviation fuel, or other liquid petroleum products over long distances. It is typically mounted on a semi-trailer chassis with multiple axles (2 to 4 or more) and features a cylindrical or elliptical tank body made of carbon steel, aluminum alloy, or stainless steel, often divided into multiple compartments for carrying different fuel types in a single trip. Fuel tank trailers are equipped with safety features such as anti-rollover devices, emergency valves, grounding reels, fire extinguishers, and pressure relief systems. They are commonly used in conjunction with a tractor unit (like a semi-truck) for fuel delivery to gas stations, airports, industrial facilities, and military bases, with capacities typically ranging from 10,000 to 50,000 liters or more.