Anyone thinking of buying these, I suggest you pass on by.

The tip area is a miserly and pathetically fragile 1mm square, nowhere near enough to absorb even the lightest touch.

And they do not seem quieter, just lower pitched.

They do however seem more economical so do improve battery duration.  Added roughly 45 seconds to a 4-5 minute at best quad.

Damn. I kinda wanted to try these on my 5” Stardust build.

Ain’t no good if it can’t handle a minor crash.

I personally think they are (were) just over-hyped and not worth the bother. The extra flight time was probably just because of the lower pitch and not the actual donut design. Also, they introduce more "loops" to get caught on branches. Exactly what you don't want on a quad.

Bob Roogi (aka KebabFPV) did a rundown on these about a month ago in the video linked to below for those who didn't already see it...

I was running comparison against visually the same pitch tri blades or as similar as far as was possible to tell.

Don't agree with his "buy two sets anyway" or his "these are pre-production, production will be stronger"

Yea, waste money on two sets...................  NOT.

I didn't hit a branch, I didn't hit the ground, one of mine broke after landing flat by contact with a longer stalk of lawn grass, I mean, REALLY?

What plonker thought only 1x1mm section at the touching point of the tip would be OK?  Pass your address, I have some reality ready bottled for you..........  

I thought that the "blade" section curved more into the vertical, not damn well disappeared, or I'd not have bought.

If a blade of grass can break one of those things, that’s a definite hard pass for me.

Thanks for the heads up.