Mainly bought for SD card reader as new imac has ...
938226
Mainly bought for SD card reader as new imac has slot on back.  card reader broke after about 5 uses.  BUYER BEWARE!!!!
3004946
My computer did not have the SD card reader. This gadget works great for my 8gb SD card from my camera. Just plug it in the USB port and it works as described. Highly recommend.
3226901
I have a mid-2010 27" iMac decktop with i3 processor. This quadrupled the RAM and made it run like new. Worth the money.
I have to add that all the installation directions and tutorials from the web/apple told me to "gently" push the cards in. My cards weren't pushed in all the way so upon start-up I thought the cards didn't work two times. Then i pushed with all of my force and the cards snapped in. So you might have to push harder on it than "gently". Maybe that instruction is for burly dudes?

I bought these: Four count of "4GB 1333MHz DDR3 SDRAM; for a total16GB"

review in May 2018
210518
I was looking for something with several easy access USB ports for my iMac, this is charging ports ONLY.  I Love it, but was disappointed when I realized I did not read well before buying.
4947629
Had been looking to replace my aging desktop's floppy drive with something more useful.  There are many card readers with this form factor; I chose this one because:

- it reads SDHC and CFlash cards
- has separate controllers for each card type
- works on Linux and NetBSD
- didn't cost over $20

Drive is completely unlabeled; my system reports it as "unknown 4-in-1 card reader (iStar) ; mfgr: Alcor Micro.  It appears Alcor just makes the controller chip(s).

Installation is similar to installing any internal bay drive; 4 screws are included but my case uses rail retainers.
Had to sand the edges of the faceplate a little to ensure a good fit through the front bezel of the case.

Cabling requires a double row USB header; I didn't have one so picked up a cheap PCI USB controller card with an internal header.  The eSATA port has it's own cable which plugs into an open SATA header.  If you don't need it just leave it unconnected.  Cables look to be about 18" long.

One thing to be aware of: the flash media slots are quite shallow which leaves approximately 75% of the card body protruding.  Doesn't look as nice but it's much easier to extract the cards.
3848089
So far so good, the other reviews on this item are really accurate. For some reason the imac only has usb ports in the back that are really hard to access so I needed a solution for that that would be able run external usb harddrives (western digital passport) and it does it perfectly. Good device for the price.

edit
I just saw that they raised the price. I bought it for 15.99 + tax :/
271490
Sure the SATA cable may not be correct, but I had one with a right angle laying around, plus they are cheap anyway.  I mainly ordered this for the power cable, seeing at they go for about $25 on ebay, this at $22 and Prime was a good deal.  Make sure you watch the video on how to do this, its not difficult, just involved.

Having my iMac now running a SSD, just gave me an excuse not to drop another $2000 on a computer.  If spending $2000, I would drop 2 1TB SSDs in the iMac and buy a Macbook Air or something.

This is a good buy for sure and should give you a number of years added to the life of your iMac.
4057429
The reader itself seems to work great, but the 128gb micro SD card does not work.  I think I might have damaged it because it would not come out of the reader.  I had to pry it out, but SanDisk, Kingston and Sony SD cards pop in and out no problem.  I would return it, but I think I am the one who damaged the card.
643595
I have spent so much time on this...first i bought an SD card, then i had to buy a different SD card, now i find that this doesn't work with Macs, there's something ELSE i have to buy.  it was a gift, so i didn't see that...i wouldn't have bought it.  argh.
4815692
that's what I call these products from LEXAR.  No error on read/write so far from transferring 7GB data back and forth at much faster transfer rate (obviously as it is USB 3 protocol) on 2013 iMacs and 2013 Mac Pros.
1807902
I bought this particular card reader because of it 4:1 highly positive user rating ratio. I inserted a Sandisk SDHC 32 card into this Lightning 3 in 1 card reader, plugged it into my iPad air, waited for a few seconds while the device seemed to be reading the card, but was disappointed to get an error message: " This iPad does not support this accessory." I wasn't surprised because I'd read this might happen, so I clicked okay and waited. After a few seconds, the "Accessory not supported"  message reappeared. I clicked okay again, and waited. In all, I tried this four times. Then I removed the card and reinserted it, but got the same error.

I've already uploaded the files to my computer, so I know the card it okay. I've previously loaded a great many files to this iPad Air using the card reader I bought from Apple when I got the iPad Air, and have since misplaced. I mention this only because it lessens the likelihood of user-error. I don't know if the problem is that this Lightning 3 in 1 card reader doesn't like my particular brand of SD card, or if this particular device is just a lemon, or the problem is something else.
1917017
I may have recieved a poor copy or a previously used SDHC card, but this card only worked after a month of use with only ~100 photos put on it.  I use an XSi and T1i Canon Rebel.  I particularly bought it for its low price and expected a brand new card but was suspect when it arrived in a "pink" casing that is definitely not like the cards that I've purchased at store retailers.  The card no longer reads nor can be read by various card readers I have.  I then purchased another Extreme III SDHC class 6 from a large store retailer and thus far have no problems in both my T1i and XSi.  Although the price may seem great, be cautious in that you may not recieve a good card.  The free Mini SD card that came with it as a free bonus was nice.  That card has no problems yet (used in a cell phone for music and media storage).
4756025
The SanDisk arrived with my order, but the SD USB Memory Card Reader 4782349 was not included.  It installed easily and I was able to mover over to it pictures I had stored, but some of the Apps couldn't be moved because they were already pre-installed.  Overall I am happy with the product, but thought the card reader was included.
855829
This 3-category Card Slots: Designed with 3 card slots, this memory card reader could read and transfer data for Micro SD,SD,and CF 3 types of card simultanously. Relieving you from the trouble of plugging in and out. USB card reader used for moving my photo's to my iMac and Mac Book Pro computers functions just as stated without any additional software required. Transfer speed of photos to computer noticeably faster than USB 2.0. Seems to be very solidly built device!
3472826
It is very good device.  Works great and looks very nice on my MacBook Air.  The only downside: I cannot read two SD at the same time.  I also own a Kingston Digital MobileLite G4 USB 3.0 Multi-Function Card Reader (https://www.amazon.com/Kingston-Digital-MobileLite-Multi-Function-FCR-MLG4/dp/B00KX4TORI/ref=sr_1_2?ie=UTF8&qid=1473159220&sr=8-2&keywords=kingston+sd+usb) and it can read both at same time.

But in general terms, the devices is very good!.
2925930
I wanted a USB 3.0 card reader for my iMac, this looks great attached to the base of my iMac with a small piece of double sided tape. Super fast.
1907470
NOTE: This review is ONLY about the MemoryMarket USB 3.0 High Speed Dual slot MicroSD and SD Memory Card reader bundled and NOT the Perfectly working SanDisk 32GB MicroSDHC Card.  The SD slot on the reader is weak and will not hold the SD card well enough to register most of the time. The Micro SD slot below the SD slot seams to work all of the time (so far)!  SanDisk makes many SD and Msd cards and has never failed me.  Amazon bundled this card with what should be a great USB 3.0 reader however MemoryMarket reader is not a reliable device.