The Goyo Aga bit is part of the lowering jaws. The Goyo Aga has a lowering action a little less important than the pessoa, due to its lever in the shape of half-moon by hanging the reins to the attachment of the bottom. And it has a neutral action (neither lowering nor lifting) by hooking them to the attachment of the top of the bit. With the shape of the rings, it has a small directional help action like a needle bit.
I think it can fit a lot of horses, but not all riders !! In fact this bit requires a fixed and very soft hand. This bit is advised for horses that have a hard and which does not react very well when one has an action on the reins.