It's a working wing, or normally it should, designed in blender. You can stretch it to your needs with free software from blender.org.Building this simple wing is easy. Scale it on your needs in blender (1 unit = 1mm), with the scale 's' button, selecting the axis with 'x', 'y' or 'z'. Then move mouse or type number for scaling. Then use export -> stl and send to your mendel/ultimaker alike :D Don't forget to drill holes in it ;)Have fun flying!