I think I've worked the scale out to be about 1/5 or 1/6th scale...
Does this sound about right ???
Let's see . . the full size Edge 540 has a wingspan of 24.4 feet. The Vectorflight has a wingspan of 5.5 feet.
http://www.zivko.com/EDGE/edge540.html
I make that a scale of approximately 22.5%.
David C.