Good, but could be counterfeit.
355642
I purchased this from a seller here, Amaxmas (fullfillment by Amazon). The battery is ok, it at least works for a couple hundred shots (albeit far less than OEM), but after a few cycles i am led to believe that this may not be genuine, or could be defective. Compared to the OEM batteries i have from my other Nikon bodies, this battery does not last as long, and even just sitting idly (outside the body) it slowly drains. Inside the body, it has drained by as much as 10% a day with the camera off -- something the OEM battery doesn't do.

Not sure how relevant it is, but there is also an ever so slight difference in the print on the back of the battery compared to the OEM ones. The hologram is also different and looks almost exactly like a fake hologram posted in numerous online forums and blogs. I've tried attaching an image from bonell.wordpress.com - http://i49.photobucket.com/albums/f288/hcornea/counterfeitnikonbattery_zpsoxgvhzt3.jpg -- my batteries look very much the same (genuine on left, with the extra numbers below the trashcan image), counterfeit on right.

For the price i paid, i'll chalk it up as a lesson learned, and will treat it like any other non-OEM battery that holds a bit of charge at a lower cost.

I'm getting just new OEM batteries from now on.
701007
These worked really well, but I questioned the authenticity of them upon arrival. They came in a bag with a beat up box in it and the three refills did not have labels on them. This may be the normal, but it seemed odd. They work fine, it just seemed like maybe they weren't actually from Tommee Tippee.
2938306
I ordered these ear muffs and quickly learned the pair I received are counterfeit. According to the manufacturer (Honeywell) the way to identify the authenticity is to look at the battery terminals. If your pairs uses springs for the battery contacts you have counterfeit ear muffs. The real version uses metal plates as seen in picture amazon displays.
3209749
If a deal seems too good to be true, it definitely is... at least six of my pins are counterfeit, and not good counterfeits at that (The knock-off of the 2012 Cinderella Perfume Bottle Hidden Mickey is really, really, really fake looking). Nearly all are Hidden Mickeys, and I'm still examining the rest to see if any of these are genuine and tradeable. Likely not.
1307200
I purchased three of these and was a little disappointed with the inconsistency of the packaging in regards to the boxes - one came with a bag, one with a box, and one without anything. All came with authenticity cards. I have no reason to believe these are fake bc Ive seen the exact ones at Nordstrom Rack. Reviewers stating the silver is too shiny or the stamping is blurry, I think are comparing them to the nickel finished bracelets.
143147
Suspected Counterfeit.

We bought 4 of these for our daughter and neices for Christmas. They were very nice quality and came in the frozen box depicted in the photos.

We just (FEB 2015) purchased another two for birthday gifts and they came in black boxes. There were separate frozen boxes, one of which did not even have the insert. These were order from Amazon and the listed as "Disney" however the new necklaces look different from our previous necklaces.

The crystals are not as large and the chain is larger and not of the same quality.

See the attached photos of the seperate boxes.

The last 4 photos show the old and new necklaces side by side.

My daughter's necklace is the one in the close up that is on the right. As you can see the snowflake is larger, the chain is finer, and the crystals are larger as well.

The manufacturer could have gone to a lower quality producer in order to meet demand but the fact that the necklaces were in a seperate boxes is very suspicious.
3002987
I think I got a fake one, so be warned. I have nothing to compare it to but based on the other reviews, the quality which didn't seem so great and the label, I think it was a fake.
809514
There is no serial number on here which indicates that this is a fake. I believe it may not be genuine, and if it is it is a very good fake. All the other signs were there to say it was authentic, except there is no serial number on the inside tag.
3005448
Appears to be an authentic SD card. Ive had trouble with counterfeits.
3604064
Works as advertised and fits as the factory ones do. Beware through, these may be knock-offs and not original Philips bulbs. The seller's listing states a certificate of authenticity is included; not true. They also came in plane white unmarked boxes with no name or logo of Philips. There is a QR code on the base of the bulb; the purpose is you are supposed to be able to scan this to ensure it is authentic. The bulbs produced no verifiable scan that indicated Philips and when I sent the image to Philips they were unable to verify the authenticity of these bulbs. So, buyer beware.
2705226
After the exchange, I'm satisfied. The last pair looked counterfeit-- the logo was off-center, but they look great now.
1069501
Counterfeit
Real luminara on the right
Counterfeit on the left
1537464
Well, my two measuring calipers that I had inherited had issues. The dial caliper would not zero easily, and I couldn't remember what battery the digital one used. Or if it worked to begin with.

Originally I was going to get a $20 unit, but I noticed that I could get a Mitutoyo unit for only 5x the price (vs. the 11x that I remembered seeing before). My experience with Mitutoyo said it would have a long, reliable life span.

I checked through reviews on here to see why a company with Mitutoyo's reputation would have surprisingly low reviews. Since there sees to be a problem with counterfeit units, I decided to check Mitutoyo's authorized distributors list.  It required a zip code, so I threw Ideal Precision's name into Google for that and verified that they are authorized and therefore unlikely to send a fake product.

Anyway, it arrived today and inspection revealed that it was indeed a genuine product.

The QR code on the rear contains the code number, model number, and serial number.
4127972
I'm not sure mine were genuine because the logo on some were missing. The inside as well was a little chipped plausibly due to packing. However overall this product works and stores my eneloop batteries. My only problem is I might have bought a pirated version.
2525960
They appear to be genuine but the feel is flimsy. I compared the 11 checks I found online to determine authenticity and almost all of them were OK except the seller didn't provide a box but instead the brown case was in a plastic bag.  The serial number on the bag does not match the number on the glasses and there's also a typo on the label so to me this is a red flag.
2530203
After I compared the one I received with the battery that came with my 5D Mk II, I saw all the signs that people have warned about counterfeit batteries: No serial numbers stamped on the label or in the little box on the left side, The fonts are all noticably different, the blue part of the back label has choppy looking corners instead of perfectly rounded corners, the black plastic isn't as shiny where the original battery is shiny, and it doesn't slide in and out of the camera as easily as the factory battery.

It took a charge and registered in the camera, but now I'm wondering if the thing will last very long or explode in my expensive camera. Even the packaging looked like it was from Canon, so the counterfeiters have this battery faked very well by now. Beware of seller "columbususa" since they were the supplier on my order.

I recently bought a 77mm lens cap here on Amazon that was supposed to be genuine Canon brand too, and it is also a knock-off. I'm really getting pissed now because I specifically sought out genuine Canon products and paid their premium prices.

Update: This morning I looked at the packaging the battery came in, and at first glance it looks like a genuine Canon box complete with instructions, but the Canon Website indicates that all genuine Canon retail products come with a hologram on the packaging that changes color when viewed at different angles. This counterfeit box contains no hologram at all, and the cardboard and printing is kind of dull compared to the high quality boxes and ink used on genuine Canon products.

Also, the yellow plastic cover that snaps on the bottom of the battery is not as stiff as the original, the color is different, and again, the fonts on it are slightly different than my original. All indications point to this being a clever fake.

Canon's own Website acknowledges that there are counterfeits being sold as genuine, so take caution when buying these. I really want to return this battery, but I don't want to pay shipping again and pay restocking fees or whatever other bureaucracy they use to get more of our money.
4813543
I do not know how to distinguish authenticity. This is I received all the things .There is no qr code. No price tag. But the work is good.