Wingtip device

A wingtip device (red) on the wing of a Boeing 747

Wingtip devices are usually intended to improve the efficiency of fixed-wing aircraft. There are several types of devices, and though they function in different manners, the intended aerodynamic effect is to modify the aircraft's wake in some beneficial manner. Wingtip devices can also improve aircraft handling characteristics. From a marketing standpoint, they are also valued for their aesthetic appeal, and aircraft have been equipped with them for cosmetic reasons as well.