These are leg extensions for the Spyda 500 CrossFire arms. These are inspired by the arms created by DennisBladwin with this thing: http://www.thingiverse.com/thing:60722 These new arms are designed to match the CrossFire arms. available for the Spyda 500. When added they will lift your quad copter an additional 80mm off the ground. This was needed for me to get my battery which I've mounted on the belly of my quad-copter out of the dirt. I have also provided the source SketchUp so that others can tweak as they see fit.