Manufacturer's Weight Empty (MWE) (also known as Manufacturer's Empty Weight (MEW) is the weight of the aircraft "as built" and includes the weight of the structure, power plant, furnishings, installations, systems and other equipment that are considered an integral part of an aircraft before additional operator items are added for operation. Basic aircraft empty weight is essentially the same and excludes any baggage, passengers, or usable fuel. Some manufacturers define this empty weight as including optional equipment, i.e. GPS units, cargo baskets, or spotlights.