I found circular prop guards didn't work very well on my ladybird v939; each time I bumped into something, they compressed a little and impacted the props. These oval guards have some space to compress without touching the props. And they sit all the way against the body of the v939, so they won't get unaligned from small nudges. If you want to use these and keep the body shell on you copter, you will need to enlarge the arm holes in the shell.Printed in PLA with 0.3mm layers and 100% infill, supports on but no raft.