I once made a brief review of it there ( http://www.kbdmania.net/xe/659717 - in Korean) and 'huha' asked me its product ids. 
VID : 13BA, PID : 0017. I hope that it will be help you. 

I'd like to write the good things and bad things here again in english briefly..

[BAD]
- It seems that we cannot use any non-standard keys in US keyboards like Hangul/Hanja with it. I've checked it via Scan Code Checker utilities and none of them were reporting those keys. 
- Simultaneous input is limited to 4 keys only(except for special keys like CTRL, ALT). Sometimes, less than that.
- If you press a key while already pressing another key, it will tell a lie as previous key have just been released. For example, if you press "A" key, hold it, and press "B" key together, your system will get the signal that tells the "A" key has just been released regardless the real state of keyboard. Really really weird. It makes you away from playing any games. Luckily, the special keys like CTRL, ALT and SHIFT don't cause this problem. Therefore definitely it's a bug of its firmware. 

[GOOD]
- Pretty cheap. 1 or 2 bucks.
- Good converting for mouses. No delay and appropriate initial pointer speed. I can even play RTS games like Warcraft III with that and so good. Finally it has become my designated converter for my obsolete Microsoft ball mouse and I always use it to play WC3. (Of course I NEVER use it as a keyboard converter.)

[OVERALL]
- I think it is worthless to buy unless you wanna many converters for server PCs in business or only for mouses. If you try it on in usual cases, it must make you get angry.

Thank you for reading. Have a nice weekend!