The fuel tank cap is the part of a vehicle that seals the fuel tank to prevent gasoline fumes from escaping into the atmosphere and allowing bugs, such as bees, wasps, or other types of debris, along with road dust to enter among other things. Its main jobs are to keep the fuel tank under constant pressure, release excessive pressure safely to avoid explosion and it is air tight too so that no vapor escapes or leaks. New fuel tank caps usually have the technical characteristics to withstand abrasion, twist-locks for security reasons, in some cases incorporated into the key a turbine with rubber hoses and also a fuel level sensor circuit. Applicable to motorcycles through heavy-duty trucks, this ensures safety and fuel efficiency.