The Cambridge Mouth Kimblewick is a bit commonly used on ponies. Kimblewicks are similar to Pelhams in their action with the use of a curb, but milder in their action due to the lack of shank.
The lack of shank on a Kimblewick bit gives far less leverage and can make them a good bit for children to use as they also have the added advantage of being able to be ridden with just one pair of reins.
The low port gives space for the tongue, with no collapse on the bars and no real palate pressure.