GFF (Gundam Fix Figuration) is another line of products by Bandai, the leading Gundam related product manufacturer. Most GFF figures are in 1-144 scale, meaning that they are quite small, around 13 - 15 cm tall, I think. Because they are small, GFF figures are quite popular in Japan and Hong Kong, since the people there got limited spaces in their houses for these accessories.
I'm not a real fan of GFF, though I must admit that some of the releases are quite impressive, for example, GFF God Gundam I would like to introduce here. Those of you who watched the anime series of Mobile Suit G Gundam will definitely know this mecha, since he is the main character in it. The storyline changed dramatically from huge battlefield in anime series like UC0079 or Zeta to Street Fighter type of Gundam duel competition. Very bizzare. Also, many kung-fu moves was used during battles, which was named in Chinese. Cool!
I didn't watch that anime series, but I do have some of the models featured, like God Gundam, Master Gundam, and Rising Gundam. I got the Master Grade God and Master, with the famous action frame feature,enabling those two models to do some kung-fu poses with no problem at all.
While the Master Grade version of God Gundam emphasized a lot on the action, GFF God Gundam seems to be focusing on heavy mecha design, i.e. very mechanical-like. Pretty impressive as well, since it gives God Gundam another interpretation, this time closer to it being a humanoid machine instead of a mechanical human being (mimicking human action which is not possible for a machine).