Have one, it came in a box full of toys from eBay. (as in I was shopping for some cables and batteries and the store had these, so I got one) They work. It's not a real flash, it's a LED light that flashes. You can use it continuous too and solve any Sync. problems. Basically I wanted it for fill on macro. I may have used it for some food shots.

$21 eBay BIN easy to find, shipped from China, comes with a slew of lens adapter rings. Everything plastic. If you grab them tight they will bind. Must be turned, not grabbed. I never considered the guide number, but 15 is optimistic. LOW!

It works, could be useful. I won't say much else. It's a little light that goes around the lens and attaches to the filter threads. For twenty-two bucks, how much fun can you stand? 

I used to have for couple of months but I found completely useless toy.
Save your money for something more serious like Canon Macro Ring Lite MR-14EX.
It's a bit expensive but ........ 100X better than Aputure Amaran.

Or consider something like a Ray Flash.  It attaches to the head of your speed light and redistributes its light around the lens.  I've used mine for years and love the results.  A whole lot easier than carrying around a studio strobe.

Thanks for the link disorderly.
I have the impression that it does not fit with Nikon flashes
(Sony, Metz, Nissin, Canon)

And yes it is surely lighter that the Boncolor one

^ Yes, this is surely better, I have found that it costs around $ 125 - 150 if I have understood well.
And the adaptor rings around $ 25 - 30 each one
So about $ 250 - 300 to use it with 3 lenses

^ no problem OM