Ok, so this bit is super cool. While it absolutely has a purpose and a function, it has such a cool look and is definitely a conversation starter. Most often called a Half & Half bit, sometimes called a rail bit, designed to be easily flipped to be used on either side of the horse. It is half stainless and half copper alloy material, with a thinner and slightly triangular edge on the alloy side. The purpose of this is to put copper side on the side/direction where the horse is a bit heavier on the bit or less responsive to rein aids. Additionally, it promotes salivation on that side if a horse is struggling to stay soft and to promote bit acceptance. This is a great training tool without correction. From Kieffer, 5″ mouth and this cool bit is in excellent used condition.