Here is the wing skid that protects your wing tip. This is not all. 
It was design to be removable. Some don't like to show their plane with wing skid on static display. You can remove skids and put in your tool box. 

The MAP Micro Air Retract system is the long awaited solution for larger electric scale planes and EDF Jets.

Airpower RA-250 Trunion Adapter for 3/16'' Wire Struts

AirPower Oleo Legs Silicone Oil Kit (#10000 / 50 ml)

The HET-RC L-39 Retracts are specially designed for the HET-RC L-39 Albatros composite EDF Jets.

The CMPro Giant Plane retracts are the perfect choice for all 120 class Warbirds offered by RC-Warbirds.

Replacement inserts for Model Aviation Products Wing Tip Skid.