The Boeing 737 is a narrow body jet airliner with short to medium range, single aisle configuration. Cabin space is designed to be both durable and flexible. Optional, convertible seats make it possible to quickly change the passenger cabin to accommodate a variety of airline seat configuration requirements. Best known for its reliability, fuel efficiency and economical performance, typically carries 146 passengers in a two-class arrangement and as many as 188 in a single-class setting.