Here we have a Genuine STIHL Air Filter Square Nut.
Fits quite a few saws, like the 041, 041S, 050, 051, 051, 075, 076, 070, 070AV, 090, 090AV, 090G etc.
A quality branded part and as such adds value to your saw.
Worth the extra IMHO

The last pic shows how it looks on the cover.

Postage Globally no worries.
Thanks for looking!

OBM AUSTRALIA