One out of four complete failure
351600
The first installed, out of four ordered, I heard a loud clacking noise that sounded like something was hitting the fan and the fan would not run. Upon inspection the blades fell off, completely separated from the fan body. My first review was rejected by amazon "I ordered four of these, one arrived shuttered in pieces, see photo. I tested the other three and run but time will tell about reliability ..."  I no longer have the photo. Also, reduced my review to one star, will revise if other fans prove to be reliable.
3566431
These are great, but one of them already failed.  Are you willing to replace failed bulbs?  I hope this was an outlier, as I would like to continue to buy these for my business.

EDIT: Another failed within a  week of another one failing.  Can I please get replacements?  Or maybe a refund at this point?  I bought sixteen of these and I'd hate if they all started dropping like flies.  They replaced LED bulbs that were fine for two years, so I know it's not the fixtures.

EDIT:  Yeah, they're all failing.  Total waste of money.
3589349
Two of the four didn't work  Will have to return. Unfortunate because I was so looking forward to tbese
3335528
3 have already failed and I've only installed 10.  30% failure rate is not good.
Update 4/4/17 - 4 more have failed.
308492
Like stated in the title.  One out of four is bad.  Other than that, everything work as advertised.
The faulty ram fails Memtest 86 and causes BSOD in windows.
DOA rarely happens to rams.  Just make sure you test them thoroughly after the purchase.
3512584
Four of the rings didn't even work. It's lucky I only need eight or I'd be returning these.
1842840
A 3 yaers ago I bought a five brand name LED  bulbs for hard to reach fixtures in my house. Today all those are still running strong.

When I saw this 10 pack, I was really excited: the price of LED bulbs had finally reached a point where I was willing to convert the rest of my house to LED. However-of these 10 bulbs, 4 of them have now failed across different light fixtures in the house. That reflects a 40% failure rate in less than 4 months.

This is really sad and while I probably just got a bad batch--I am not going to buy these again. This is my first one star review--and hopefully my last.
155045
high defect rate. Had two of three that wouldn't work
3842783
I ordered a few of these to give as gifts to family with my wedding photos on them. Three out of four seem to be working fine, but one has completely failed. All of the photos disappeared from the drive, and the drive can no longer be read, written to or even re-formatted. These are nice to look at, but I highly recommend having backups of any files you save on them.
2189666
One out of the five cables had the interlocking device missing, so QA is less than desirable.  20 % fail rate is pretty bad.  I can only hope the cable themselves are ok and work.  We'll see I guess.
4451109
One was DOA, other three failed in 4 weeks. Amazon says currently unavailable. Not surprising, but if they start selling again, save your money. Total crap.
4031252
Only three of the five worked. Two had bad switches that would not turn off. The ones that worked were fine.
1634067
Most worked fine. Only one out of ten was DOA.
3821595
I have two of them that haven't worked so far but the other 4 i have used worked fine..
2516600
Some worked while other didn't.... It would have been Awesome if they all worked...
380082
Out of the first 4, one was DOA and just buzzed instead of siren and another fell off a vinyl framed sliding door (where 2 others stayed stuck on identical doors in same sunroom). I'm anticipating the others will need additional adhesive to hold through all four seasons of WI weather.

I'm not giving-up hope and will update my review as I install more of the 12 units purchased. A couple will be installed on woodframe windows and may stick sufficiently, the battery life will be a concern as well. One location (cottage) will be vacant for extended periods with these only as a "hopeful" deterrent as any problems that might arise are likely juveniles committing petty burglary.
1051406
Purchased a batch of six from Amazon August 5. Received and installed in early September. All six failed by October 23, with only 2-3 hours use per day. I'd call that a very high failure rate!