Pros: A reasonable quality track-2 only card reader. Plugged it into a free USB port and it recognized right away. Ran all my cards through it and it didn't have any trouble reading any of them. The USB cable is nice and long, and unlike the rest of the unit, feels pretty sturdy.

Cons: Despite the title, it only reads track 2 and will only ever read track 2. I took it apart to check out the internals and it has a single track read head and an strange 3-wire interface (unlike the usual 5 you'd find on an Omron) to the mainboard with the microcontroller which does the parsing. It's also bigger than I expected from the photos and is quite light. It doesn't scream quality.

Other Thoughts: The third dip switch I can confirm does nothing for this unit. They use the same mainboard for different units and the switch is for use in their 1/2 and 2/3 track models.
I also was unable to get this working in Linux. dmesg indicated that it recognized it as a keyboard HID but the green light wouldn't stop flashing and it wouldn't read cards.

Bottomline: I wouldn't suggest using this for POS in the real world, it's just not sturdy enoughbut for $20 its fun to mess around with.

Pros: Easy to use. Just plug it into a USB port and swipe a card. Acts like a keyboard, so the magstipe data is "typed" right on the screen.

Cons: Product title says this is a 3-track reader, but read the detailed description - it only reads track 2. This seems a bit deceptive.
Manual is in Chinese, but it's not really needed. Just plug it in and it works.

Other Thoughts: Build quality is good, although I'm not sure that it would stand up to heavy daily use. Just fine for low to medium volume environments.

Bottomline: Just fine as long as you only need to read track 2.