The Boeing 737-700 is a narrow-body airliner and a variant of the 737 Next Generation series. This variant, like other 737s in the Next Generation series, features upgraded engines and overall improvements however it's fuselage is almost exactly the same of the Boeing 737-300 making it possible for it to be a like-for-like replacement for that variant from the Classic series. The (WL) designation stands for Winglets which were not standard on initial models but introduced on later models as standard or retrofits. The Boeing 737-700 is the second shortest variant but is the second most popular variant of the Next Generation series. The Boeing 737-700, along with the it's -800 sister variant, have become the backbone of narrow-body fleets of airlines around the world. The Boeing 737-700 typically flies short to medium haul flights that have medium to high demand. The Boeing 737-700 is no longer in production.