How can i tell if my Helly Hansen jacket is fake or not?

I bought it from E-bay, but the logo on the hood at the back looks really small and it only cost 拢20, BNWT.|||its really hard to tell nowadays..i bought a tag huer watch a really expensive one and i examined it with a fake one at a top brand watch shop and even the top watch shop could not see any difference,|||Bite it like an ol' prospecter. If it's rock hard it's fake. Yeeee-haaaaa.|||Wow, I had one of them about 4 years ago, who still wears them ?? x|||eBay + 拢20 + top brand name like Helly Hansen = fake|||who still wears them ?