Rivets are so cheap it doesn't make any sense to buy them from other than a reputable supplier. When I buy from Spencer Aircraft (great service) all their hardware comes with a lot number for traceability purposes. Vans doesn't do that but I trust they aren't stocking no-name untraceable hardware. Treaceability doesn't legally affect us as homebuilders but I believe it is mandatory for the military and airlines. I am told that counterfeit aircraft hardware is a problem, also counterfeit aircraft parts, too. Incidently, I would recommend against buying pharmaceuticals on the internet. Same deal. (The dimple indicates the rivet is made of 2117 aluminum alloy, an "AD" rivet.)