I buyed two sets of Sigma Pro flight and I'm trying to found the right set. I only used it with my 48mm stems but I'm not feel so confident cause darts fly not very straight (hope I'm clear) (maybe because the area is smaller then the Harrow Combat I used before?). Can things improve with shortest stems, to move the centre of gravity? Another thing: I'm totally unable to put flight protector in it, it's normal or it's just my fault?

You have to experiment with differenct sizes on stems and different shapes on flights. The unicorn flight selector kit is quite handy for this. It's under the unilab part of the website

Could be because the flights are small, when I tried the Sigma Pro Carbon with the Sigma flights the darts seemed to fly a lot quicker through the air.

Do you throw fast are slow?, maybe they are not suited to your throw, but wont hurt to try a different size stem.

Thanks for the answers. And what about putting the flight protectors?

What about them?

This:

Franz wrote:

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I'm totally unable to put flight protector in it, it's normal or it's just my fault?

It takes some concentration. Are they half flight protects or the proper metal ones?

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Them or these
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The second ones

They're tricky. Need time and concentrate a lot

I dont use flight protectors, they are a pain when they come off and get lost.

They're quite handy until then. My gold aliminium ones that I've put on have lasted months and haven't lost any

for me, the unicorn sigma pro flights suits my lighter darts (16g) better than the heavier ones. i get inconsistent angles when used with my heavy darts (25g-26g)