ORIGINAL: jay1st
With these plastic wing tips, you can glue them or/and screw them as well.
I have them on a low wing trainer used a some kind of test bed/no care/ stunt plane.
I've used them on planes ranging in size from .25's through 50cc composites.
I've put them on every plane I own.
The key is to install them AFTER the plane is built so you can test the points of potential ground contact.
You want the guards at the lowest point where the wing may contact the ground during a ground loop, etc.
Installed properly they are great. No wing tip damage what-so-ever.