The Junior Cowhorse
The Junior Cowhorse is a moderate gag bit that is popular for the transition between a snaffle and a curb bit in a young horse. The two-piece jointed "snaffle" mouth, three-piece dogbone, and chain are the most common mouthpieces, but there are many other varieties. When used with a leather curb adjusted loosely, it is a very forgiving bit as it gives a signal to the mouth before fully engaging and putting pressure under the chin.
Everything about this bit is in moderation--the shanks are off a medium length, they are slightly curved, and there is only a little curb action. This means that the Junior Cowhorse isn't a particularly harsh bit compared with some others on the market. It also makes it a good transition bit into a gag, draw, shanked, or curb bit.
If you are using this bit as a transition from a snaffle, it is best to start with a leather curb strap and the same mouthpiece your horse is already used to. However, this bit is also used with great success on broke, finished horses as it has a lot of lift and keeps them light. Like many gag bits, it's great for "pick up" and lateral movement, and is popular with trainers, ropers, and other speed event folks.
Read more: My Own Informative Bits and Bitting Thread