Why did you post that!? Ugh, thanks... you just blew my shot out of a UK Pocket Reversi for very cheap... Once again, thanks...
Anyway, That is a UK Pocket Reversi. One way you can tell from a UK from US from JAP, is that the Japanese games have Japanese text on the boxes and carts. The UK and US are all in english, but the UK has a little rainbow thing in the top right, which some Japanese games have, but no US games have. Also, all UK games have the clamshell type box, while the US version have Cardboard, and the Japanese have both.
EDIT:
BTW, how much did you get it for? Pretty much anything 200 and under is considered a good price, I guess.