It technically falls into the pelham family because two sets of reins can be used. However with such use as this the reins would be place on the lower shanked rein holes. If one wanted more of a "snaffle" action you could put the reins on the D. The forward set of the mouth peice is designed to "hug" the bars of the mouth with a little bit of releif and puts pressure on the poll and less on the mouth when engaged. The length of the shanks would do that anyways. Some horses do very well with such bits and some do not. This supposedly encourages a more relaxed jaw, head carriage and so forth but IMO they are over rated. I beleive B. Imus has passed on so getting the products might be tough. I don't know whats going on with that though.
"The question is not, can they reason? nor, can they talk? but, can they suffer?" Jeremy Bentham