A winglet is a type of part used to provide stabilization for rockets and planes inside an atmosphere. It is smaller than a regular wing, hence the name, and is sometimes steerable. Such steerable winglets are then called control surfaces.
Placing too many winglets may end up producing too much drag, adding stress to the rocket and making it more difficult to control.
Currently the following non-controllable stock winglets are available in KSP:
|AV-T1 Winglet||500||0.04||2 000||12||0.3||No|
|Tail Fin||600||0.13||2 000||12||0.61||Yes|