I'm not vouching for mentalkicks, but I can say they stand by their word. I ordered an extra pair of concords from them in January. I put them side by side my pair from nike.com....and honestly I saw no difference minus the horrible smell from the glue or chemicals used. I contacted mentalkicks and asked for my money back because I thought they were fake because of the smell. No questions asked they gave me my money back. Fast forward to the next month in February when I bought my cement 4's from finishline. THE 4'S HAD THE SAME HORRIBLE SMELL THE CONCORD'S FROM MENTALKICKS AND THE 4'S CAME FROM A RETAIL LEGIT STORE!! It just had me thinking that maybe the concord's from mentalkicks were legit. Either way, I told myself if I had to question authenticity, then I just will never order from a site again.