The Kimberwick (also known as a Kimblewick) is somewhat similar to a pelham bit, in that it tries to combine the action of snaffle and curb into one bit, and in this case, through one rein. The mouthpiece is typically ported, like a curb, the cheeks are D-shaped with the moutpiece attaching to the upper part of the “D,” the cheek piece of the bridle attaches to an eye above the D-ring and has hooks for a curb chain.
This combination of ported mouth, slight leverage from the D-ring (much greater than on a D-ring snaffle because of the off-set placement of the mouthpiece), and curb chain basically make this a mild form of curb bit. Additionally, most Kimberwicks have two slots on the loop of the D-ring, so that the rein may be attached higher or lower, depending on how much leverage is required – the lower attachment affording greater leverage, very similar to a short-shanked curb.